Original Research

Most studies include a measure of the significance of treatment effects such as a P value or confidence interval (CI). CIs (Journal of family practice, December 2003, 53:970) are usually preferred to P values, which have notable limitations.

1. P values are easily misinterpreted

A P value is the probability of obtaining a result (usually a difference between treatments) as large or larger than that observed in a study if the null hypothesis (ie, no difference exists between treatments) is true. Differences in treatment effects can be expressed as absolute differences or as odds ratios. No difference, for example, corresponds to an absolute difference of zero or an odds ratio of 1.0.

Consider a recent primary care study from the UK comparing the effectiveness of different lipid-lowering drugs to simvastatin.¹ The odds ratio for achieving a cholesterol level ≤5 mmol/L with pravastatin compared with simvastatin was 0.58, with a P value of .003 (ie, simvastatin superior to pravastatin). This means that if there is no difference between pravastatin and simvastatin (ie, null hypothesis is true), the probability of getting an odds ratio of 0.58 or less is just .003 (0.3%).

A P<.05 (sometimes <.01) is usually considered to be sufficient evidence to reject the null hypothesis. This is not intuitively obvious and does not appear to provide useful information.

Many clinicians misinterpret the P value “backwards” as the probability of the null hypothesis assuming the results. In the example above, the misinterpretation would be that there is a 0.3% probability of there being no difference between simvastatin and pravastatin based on the results. Misinterpreting the P value in this way is serious, since the true probability of the null hypothesis based on the results is often much greater than the P value.

2. P values tell us nothing about the magnitude of a significant difference

In the example above, the odds ratio of 0.58, P=.003 has a 95% CI of 0.40​0.83. The confidence interval, unlike the P value, provides a measure of the precision of the odds ratio.

3. P values are very sensitive to sample size

A small difference between 2 treatments that is clinically insignificant (eg, 1-week difference in mean life expectancy between 2 lipid-lowering treatments) may have a statistically significant P value (ie, <.05) if the sample size is large enough. P values, therefore, can exaggerate the significance of results.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15361. E-mail: [email protected].

Most studies include a measure of the significance of treatment effects such as a P value or confidence interval (CI). CIs (Journal of family practice, December 2003, 53:970) are usually preferred to P values, which have notable limitations.

1. P values are easily misinterpreted

A P value is the probability of obtaining a result (usually a difference between treatments) as large or larger than that observed in a study if the null hypothesis (ie, no difference exists between treatments) is true. Differences in treatment effects can be expressed as absolute differences or as odds ratios. No difference, for example, corresponds to an absolute difference of zero or an odds ratio of 1.0.

Consider a recent primary care study from the UK comparing the effectiveness of different lipid-lowering drugs to simvastatin.¹ The odds ratio for achieving a cholesterol level ≤5 mmol/L with pravastatin compared with simvastatin was 0.58, with a P value of .003 (ie, simvastatin superior to pravastatin). This means that if there is no difference between pravastatin and simvastatin (ie, null hypothesis is true), the probability of getting an odds ratio of 0.58 or less is just .003 (0.3%).

A P<.05 (sometimes <.01) is usually considered to be sufficient evidence to reject the null hypothesis. This is not intuitively obvious and does not appear to provide useful information.

Many clinicians misinterpret the P value “backwards” as the probability of the null hypothesis assuming the results. In the example above, the misinterpretation would be that there is a 0.3% probability of there being no difference between simvastatin and pravastatin based on the results. Misinterpreting the P value in this way is serious, since the true probability of the null hypothesis based on the results is often much greater than the P value.

2. P values tell us nothing about the magnitude of a significant difference

In the example above, the odds ratio of 0.58, P=.003 has a 95% CI of 0.40​0.83. The confidence interval, unlike the P value, provides a measure of the precision of the odds ratio.

3. P values are very sensitive to sample size

A small difference between 2 treatments that is clinically insignificant (eg, 1-week difference in mean life expectancy between 2 lipid-lowering treatments) may have a statistically significant P value (ie, <.05) if the sample size is large enough. P values, therefore, can exaggerate the significance of results.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15361. E-mail: [email protected].

Most studies include a measure of the significance of treatment effects such as a P value or confidence interval (CI). CIs (Journal of family practice, December 2003, 53:970) are usually preferred to P values, which have notable limitations.

1. P values are easily misinterpreted

A P value is the probability of obtaining a result (usually a difference between treatments) as large or larger than that observed in a study if the null hypothesis (ie, no difference exists between treatments) is true. Differences in treatment effects can be expressed as absolute differences or as odds ratios. No difference, for example, corresponds to an absolute difference of zero or an odds ratio of 1.0.

Consider a recent primary care study from the UK comparing the effectiveness of different lipid-lowering drugs to simvastatin.¹ The odds ratio for achieving a cholesterol level ≤5 mmol/L with pravastatin compared with simvastatin was 0.58, with a P value of .003 (ie, simvastatin superior to pravastatin). This means that if there is no difference between pravastatin and simvastatin (ie, null hypothesis is true), the probability of getting an odds ratio of 0.58 or less is just .003 (0.3%).

A P<.05 (sometimes <.01) is usually considered to be sufficient evidence to reject the null hypothesis. This is not intuitively obvious and does not appear to provide useful information.

Many clinicians misinterpret the P value “backwards” as the probability of the null hypothesis assuming the results. In the example above, the misinterpretation would be that there is a 0.3% probability of there being no difference between simvastatin and pravastatin based on the results. Misinterpreting the P value in this way is serious, since the true probability of the null hypothesis based on the results is often much greater than the P value.

2. P values tell us nothing about the magnitude of a significant difference

In the example above, the odds ratio of 0.58, P=.003 has a 95% CI of 0.40​0.83. The confidence interval, unlike the P value, provides a measure of the precision of the odds ratio.

3. P values are very sensitive to sample size

A small difference between 2 treatments that is clinically insignificant (eg, 1-week difference in mean life expectancy between 2 lipid-lowering treatments) may have a statistically significant P value (ie, <.05) if the sample size is large enough. P values, therefore, can exaggerate the significance of results.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15361. E-mail: [email protected].

► About: “Laparoscopic cholecystectomy in a rural family practice”

On the surface, the previous article by Haynes et al¹ appears to be a simple descriptive study of a well-established technology. So why publish something that is not new? Simply because the study is an incredible technical and political achievement in a JCAHO-accredited hospital by a family physician educator. All family physicians—whether they view themselves as “procedural” or not—should recognize it for its symbolic and political value.

High-touch and high-tech

If family physicians wish to provide more than “generic primary care,” they must provide clinical skills at the bedside, in addition to diagnostic and psychosocial expertise. No amount of the latter will compensate for the former at critical moments. For credibility in the community and in the life cycle of families, the provision of diagnostic and therapeutic procedures trumps prescription-writing every time.

By providing surgical or diagnostic procedures that improve access to health care in their communities, physicians such as Haynes are not regressing to a surgical mentality at the expense of psychosocial sensitivity and therapeutic listening. Our closest relations with patients and their families are established at the bedside while performing or assisting with a diagnostic or therapeutic procedure. Procedures frequently provide the ultimate “teachable moment.” As said at Keystone III: “You can pretend to know; you can pretend to care; but you can’t pretend to be there.”²

Also, procedures distinguish family physicians from the other “primary care providers” who are hired with the assumption that they will provide referrals. Patients will seek out those physicians who can simultaneously provide high-touch and high-tech.

1960s–1970s: The growth of high-tech

During the 1960s and 1970s, advances in technology were predominantly located in hospitals. The traditional office-based diagnostic and surgical skills of the general physician were gradually transferred to a more central place, namely the hospital. Many of these skills were then categorically assigned to more specialized physicians resulting in the withdrawal of the generalist physician in the participation of these skills.

Originally, family medicine educators thought the 3-year curriculum would be sufficient for procedural training, but they underestimated the political passion for control by opposing specialties with a need to maintain their training monopolies. Among 20 voting specialties, family medicine has only 1 vote. This is the democratic reality, which frames any potential turf struggle in a highly subspecialized environment. These environments include, but are not limited to, academic medical centers, most urban hospitals, and some rural hospitals.

The institutionalization of these interventions depersonalized the patient-doctor relationship, limited access, and escalated cost. Family practice as an emerging specialty willingly joined in this movement, resulting in the abandonment of many generalist-appropriate skills. During that time, studies of how tertiary-care technologies might transfer into the community were undertaken.^3,4

It became increasingly evident that many diagnostic and interventional procedures (eg, diagnostic ultrasound, gastrointestinal endoscopy, and colposcopy) had multiple-specialty applications and were clearly linked with important preventive activities. ^5,6 Some leaders suggested that technical skills combined with the unique biopsychosocial model of practice of family physicians was the right way to provide competent, personal care to patients. In other words, high-tech was most effective when blended with high-touch and vice-versa. ^7-9

1980s–1990s: The FP curriculum expands

In 1981, the first in a series of fourth-year fellowships emphasizing this expanded curriculum for family physicians was initiated.^10-12 Thereupon followed the development of CAQ experiences in Geriatric Medicine and Sports Medicine, which, while instructive, failed to create added market value to most rural and under-served communities. The American Academy of Family Physicians—through the Task Force on Obstetrics (1989–1993)¹³ and then the Task Force on Procedures (1993–1995)—ratified and distributed performance-based learning and competency-based testing programs. Moreover, the Advanced Life Support in Obstetrics (ALSO) program had a major impact nationally and internationally.¹⁴

By 1991, our discipline was focused on credentialing for lightning rod issues such as colonoscopy,¹⁵ esophagogastroduodenoscopy,¹⁶ colposcopy,¹⁷ obstetric ultrasound,¹⁸ and cesarean section.¹⁹ In Memphis, because of the political conflict associated with the teaching of diagnostic ultrasound, gastrointestinal endoscopy, and cesarean section, we chose not to “fan the flames” with development of office-based laparoscopy. But we were ready. We included laparoscopic tubal ligation in our FP/OB fellowship, but the resistance from specialties who felt family medicine was invading “their turf” was difficult and remains so.^20-24

By 1995, the Residency Review Committee for Family Medicine had codified the rural training tracks²⁵ and reaffirmed OB-capable faculty as part of the accreditation process. These advanced family practice curriculum needs were acknowledged, and various educational innovations with an emphasis on skills needed for success in rural or urban underserved communities began to emerge.^26,27

Nebraska,²⁸ Marshall University,²⁹ and the University of Tennessee–Memphis ³⁰ have summarized their experiences with the accelerated residency program and rural training tracks have done the same. These programs have recognized the need to train our future teachers and role models broadly, combating the “learned helplessness” that too often characterizes our training environments when we leave this teaching to subspecialists.

Meeting the needs of a rural practice

Some physicians with a more limited scope of practice appear threatened by proceduralists. While there is room for everyone in the big tent of family medicine, if our specialty is to survive and be credible, we must seek to meet the needs of our patients and our students. In most urban areas, family medicine has abandoned large parts of our patients’ care to the specialties of emergency medicine and obstetrics/gynecology.

From the rural perspective, it is impractical or fiscally impossible to recruit and maintain platoons of obstetricians and board-certified emergency medicine specialists to counties not located near a metropolitan area.^31,32 Family physicians, if properly trained, are the ideal physicians for nonmetropolitan practice.

Moreover, the current practice management curriculum in most family practice residencies is a do-it-yourself suicide kit where few physicians understand accountability measures for billing, collections, equipment, and human resources. They may have memorized the entire amino acid sequence for the human genome, but they don’t have the time to understand billing for Medicaid or the impact of providing a full range of services to their patients. What’s wrong with this picture?

FPs must adapt to serve their patients

The net result of the production of our graduates lacking technical skills is an overstocked urban job pool and a shortage of rural physicians. There are few 9-to-5 family practice jobs available in urban areas like Nashville and Memphis for limited generalists. On the other hand, there are jobs for every family physician willing to work after 5 P.M. This includes continuing care, urgent care, and middle-of-the-night hospital care. Procedural skills and hospital service predictably require “extra effort” and extra risk. Reimbursement policies continue to favor those physicians who assume these risks and provide these services.^33.34

Another result of following the path of least resistance (as reflected in nonprocedural family medicine is the decreasing student interest in family medicine.³⁵

Responsibility also rests with unskilled faculty who will not perform a broader scope of practice within the medical specialty of family medicine. There is personal risk for “being there” at the critical moment of procedural decisions. Students do not automatically shun this risk, but family medicine may be self-selecting for those who do.

Family physicians practicing in diverse geographic, social, and political environments will naturally adopt various diagnostic and therapeutic modalities in the service of their patients. It is not up to us to judge the appropriateness of those modalities except by the ultimate yardstick of the quality of the end result.

We are not advocating the addition of laparoscopic cholecystectomy to the “required” family medicine curriculum. However, we support the right of John Haynes to practice this skill and to teach it to others to the benefit of patients. The specialty that cannot provide training and credentials for its own members has been reproductively sterilized.^36,37 This is a unique market niche ideally suited for family medicine.^38,39

Procedurally trained family physicians represent the cutting edge of an emerging paradigm of care that includes ambulatory surgery, maternity care, cesarean section, and laparoscopy, particularly for patients in smaller communities and developing nations. We salute John Haynes and his co-authors for taking “the road less traveled.”

Corresponding author
Wm. MacMillan Rodney, MD, 6575 Black Thorne Cove, Memphis, TN 38119. E-mail: [email protected].

► About: “Laparoscopic cholecystectomy in a rural family practice”

On the surface, the previous article by Haynes et al¹ appears to be a simple descriptive study of a well-established technology. So why publish something that is not new? Simply because the study is an incredible technical and political achievement in a JCAHO-accredited hospital by a family physician educator. All family physicians—whether they view themselves as “procedural” or not—should recognize it for its symbolic and political value.

High-touch and high-tech

If family physicians wish to provide more than “generic primary care,” they must provide clinical skills at the bedside, in addition to diagnostic and psychosocial expertise. No amount of the latter will compensate for the former at critical moments. For credibility in the community and in the life cycle of families, the provision of diagnostic and therapeutic procedures trumps prescription-writing every time.

By providing surgical or diagnostic procedures that improve access to health care in their communities, physicians such as Haynes are not regressing to a surgical mentality at the expense of psychosocial sensitivity and therapeutic listening. Our closest relations with patients and their families are established at the bedside while performing or assisting with a diagnostic or therapeutic procedure. Procedures frequently provide the ultimate “teachable moment.” As said at Keystone III: “You can pretend to know; you can pretend to care; but you can’t pretend to be there.”²

Also, procedures distinguish family physicians from the other “primary care providers” who are hired with the assumption that they will provide referrals. Patients will seek out those physicians who can simultaneously provide high-touch and high-tech.

1960s–1970s: The growth of high-tech

During the 1960s and 1970s, advances in technology were predominantly located in hospitals. The traditional office-based diagnostic and surgical skills of the general physician were gradually transferred to a more central place, namely the hospital. Many of these skills were then categorically assigned to more specialized physicians resulting in the withdrawal of the generalist physician in the participation of these skills.

Originally, family medicine educators thought the 3-year curriculum would be sufficient for procedural training, but they underestimated the political passion for control by opposing specialties with a need to maintain their training monopolies. Among 20 voting specialties, family medicine has only 1 vote. This is the democratic reality, which frames any potential turf struggle in a highly subspecialized environment. These environments include, but are not limited to, academic medical centers, most urban hospitals, and some rural hospitals.

The institutionalization of these interventions depersonalized the patient-doctor relationship, limited access, and escalated cost. Family practice as an emerging specialty willingly joined in this movement, resulting in the abandonment of many generalist-appropriate skills. During that time, studies of how tertiary-care technologies might transfer into the community were undertaken.^3,4

It became increasingly evident that many diagnostic and interventional procedures (eg, diagnostic ultrasound, gastrointestinal endoscopy, and colposcopy) had multiple-specialty applications and were clearly linked with important preventive activities. ^5,6 Some leaders suggested that technical skills combined with the unique biopsychosocial model of practice of family physicians was the right way to provide competent, personal care to patients. In other words, high-tech was most effective when blended with high-touch and vice-versa. ^7-9

1980s–1990s: The FP curriculum expands

In 1981, the first in a series of fourth-year fellowships emphasizing this expanded curriculum for family physicians was initiated.^10-12 Thereupon followed the development of CAQ experiences in Geriatric Medicine and Sports Medicine, which, while instructive, failed to create added market value to most rural and under-served communities. The American Academy of Family Physicians—through the Task Force on Obstetrics (1989–1993)¹³ and then the Task Force on Procedures (1993–1995)—ratified and distributed performance-based learning and competency-based testing programs. Moreover, the Advanced Life Support in Obstetrics (ALSO) program had a major impact nationally and internationally.¹⁴

By 1991, our discipline was focused on credentialing for lightning rod issues such as colonoscopy,¹⁵ esophagogastroduodenoscopy,¹⁶ colposcopy,¹⁷ obstetric ultrasound,¹⁸ and cesarean section.¹⁹ In Memphis, because of the political conflict associated with the teaching of diagnostic ultrasound, gastrointestinal endoscopy, and cesarean section, we chose not to “fan the flames” with development of office-based laparoscopy. But we were ready. We included laparoscopic tubal ligation in our FP/OB fellowship, but the resistance from specialties who felt family medicine was invading “their turf” was difficult and remains so.^20-24

By 1995, the Residency Review Committee for Family Medicine had codified the rural training tracks²⁵ and reaffirmed OB-capable faculty as part of the accreditation process. These advanced family practice curriculum needs were acknowledged, and various educational innovations with an emphasis on skills needed for success in rural or urban underserved communities began to emerge.^26,27

Nebraska,²⁸ Marshall University,²⁹ and the University of Tennessee–Memphis ³⁰ have summarized their experiences with the accelerated residency program and rural training tracks have done the same. These programs have recognized the need to train our future teachers and role models broadly, combating the “learned helplessness” that too often characterizes our training environments when we leave this teaching to subspecialists.

Meeting the needs of a rural practice

Some physicians with a more limited scope of practice appear threatened by proceduralists. While there is room for everyone in the big tent of family medicine, if our specialty is to survive and be credible, we must seek to meet the needs of our patients and our students. In most urban areas, family medicine has abandoned large parts of our patients’ care to the specialties of emergency medicine and obstetrics/gynecology.

From the rural perspective, it is impractical or fiscally impossible to recruit and maintain platoons of obstetricians and board-certified emergency medicine specialists to counties not located near a metropolitan area.^31,32 Family physicians, if properly trained, are the ideal physicians for nonmetropolitan practice.

Moreover, the current practice management curriculum in most family practice residencies is a do-it-yourself suicide kit where few physicians understand accountability measures for billing, collections, equipment, and human resources. They may have memorized the entire amino acid sequence for the human genome, but they don’t have the time to understand billing for Medicaid or the impact of providing a full range of services to their patients. What’s wrong with this picture?

FPs must adapt to serve their patients

The net result of the production of our graduates lacking technical skills is an overstocked urban job pool and a shortage of rural physicians. There are few 9-to-5 family practice jobs available in urban areas like Nashville and Memphis for limited generalists. On the other hand, there are jobs for every family physician willing to work after 5 P.M. This includes continuing care, urgent care, and middle-of-the-night hospital care. Procedural skills and hospital service predictably require “extra effort” and extra risk. Reimbursement policies continue to favor those physicians who assume these risks and provide these services.^33.34

Another result of following the path of least resistance (as reflected in nonprocedural family medicine is the decreasing student interest in family medicine.³⁵

Responsibility also rests with unskilled faculty who will not perform a broader scope of practice within the medical specialty of family medicine. There is personal risk for “being there” at the critical moment of procedural decisions. Students do not automatically shun this risk, but family medicine may be self-selecting for those who do.

Family physicians practicing in diverse geographic, social, and political environments will naturally adopt various diagnostic and therapeutic modalities in the service of their patients. It is not up to us to judge the appropriateness of those modalities except by the ultimate yardstick of the quality of the end result.

We are not advocating the addition of laparoscopic cholecystectomy to the “required” family medicine curriculum. However, we support the right of John Haynes to practice this skill and to teach it to others to the benefit of patients. The specialty that cannot provide training and credentials for its own members has been reproductively sterilized.^36,37 This is a unique market niche ideally suited for family medicine.^38,39

Procedurally trained family physicians represent the cutting edge of an emerging paradigm of care that includes ambulatory surgery, maternity care, cesarean section, and laparoscopy, particularly for patients in smaller communities and developing nations. We salute John Haynes and his co-authors for taking “the road less traveled.”

Corresponding author
Wm. MacMillan Rodney, MD, 6575 Black Thorne Cove, Memphis, TN 38119. E-mail: [email protected].

► About: “Laparoscopic cholecystectomy in a rural family practice”

On the surface, the previous article by Haynes et al¹ appears to be a simple descriptive study of a well-established technology. So why publish something that is not new? Simply because the study is an incredible technical and political achievement in a JCAHO-accredited hospital by a family physician educator. All family physicians—whether they view themselves as “procedural” or not—should recognize it for its symbolic and political value.

High-touch and high-tech

If family physicians wish to provide more than “generic primary care,” they must provide clinical skills at the bedside, in addition to diagnostic and psychosocial expertise. No amount of the latter will compensate for the former at critical moments. For credibility in the community and in the life cycle of families, the provision of diagnostic and therapeutic procedures trumps prescription-writing every time.

By providing surgical or diagnostic procedures that improve access to health care in their communities, physicians such as Haynes are not regressing to a surgical mentality at the expense of psychosocial sensitivity and therapeutic listening. Our closest relations with patients and their families are established at the bedside while performing or assisting with a diagnostic or therapeutic procedure. Procedures frequently provide the ultimate “teachable moment.” As said at Keystone III: “You can pretend to know; you can pretend to care; but you can’t pretend to be there.”²

Also, procedures distinguish family physicians from the other “primary care providers” who are hired with the assumption that they will provide referrals. Patients will seek out those physicians who can simultaneously provide high-touch and high-tech.

1960s–1970s: The growth of high-tech

During the 1960s and 1970s, advances in technology were predominantly located in hospitals. The traditional office-based diagnostic and surgical skills of the general physician were gradually transferred to a more central place, namely the hospital. Many of these skills were then categorically assigned to more specialized physicians resulting in the withdrawal of the generalist physician in the participation of these skills.

Originally, family medicine educators thought the 3-year curriculum would be sufficient for procedural training, but they underestimated the political passion for control by opposing specialties with a need to maintain their training monopolies. Among 20 voting specialties, family medicine has only 1 vote. This is the democratic reality, which frames any potential turf struggle in a highly subspecialized environment. These environments include, but are not limited to, academic medical centers, most urban hospitals, and some rural hospitals.

The institutionalization of these interventions depersonalized the patient-doctor relationship, limited access, and escalated cost. Family practice as an emerging specialty willingly joined in this movement, resulting in the abandonment of many generalist-appropriate skills. During that time, studies of how tertiary-care technologies might transfer into the community were undertaken.^3,4

It became increasingly evident that many diagnostic and interventional procedures (eg, diagnostic ultrasound, gastrointestinal endoscopy, and colposcopy) had multiple-specialty applications and were clearly linked with important preventive activities. ^5,6 Some leaders suggested that technical skills combined with the unique biopsychosocial model of practice of family physicians was the right way to provide competent, personal care to patients. In other words, high-tech was most effective when blended with high-touch and vice-versa. ^7-9

1980s–1990s: The FP curriculum expands

In 1981, the first in a series of fourth-year fellowships emphasizing this expanded curriculum for family physicians was initiated.^10-12 Thereupon followed the development of CAQ experiences in Geriatric Medicine and Sports Medicine, which, while instructive, failed to create added market value to most rural and under-served communities. The American Academy of Family Physicians—through the Task Force on Obstetrics (1989–1993)¹³ and then the Task Force on Procedures (1993–1995)—ratified and distributed performance-based learning and competency-based testing programs. Moreover, the Advanced Life Support in Obstetrics (ALSO) program had a major impact nationally and internationally.¹⁴

By 1991, our discipline was focused on credentialing for lightning rod issues such as colonoscopy,¹⁵ esophagogastroduodenoscopy,¹⁶ colposcopy,¹⁷ obstetric ultrasound,¹⁸ and cesarean section.¹⁹ In Memphis, because of the political conflict associated with the teaching of diagnostic ultrasound, gastrointestinal endoscopy, and cesarean section, we chose not to “fan the flames” with development of office-based laparoscopy. But we were ready. We included laparoscopic tubal ligation in our FP/OB fellowship, but the resistance from specialties who felt family medicine was invading “their turf” was difficult and remains so.^20-24

By 1995, the Residency Review Committee for Family Medicine had codified the rural training tracks²⁵ and reaffirmed OB-capable faculty as part of the accreditation process. These advanced family practice curriculum needs were acknowledged, and various educational innovations with an emphasis on skills needed for success in rural or urban underserved communities began to emerge.^26,27

Nebraska,²⁸ Marshall University,²⁹ and the University of Tennessee–Memphis ³⁰ have summarized their experiences with the accelerated residency program and rural training tracks have done the same. These programs have recognized the need to train our future teachers and role models broadly, combating the “learned helplessness” that too often characterizes our training environments when we leave this teaching to subspecialists.

Meeting the needs of a rural practice

Some physicians with a more limited scope of practice appear threatened by proceduralists. While there is room for everyone in the big tent of family medicine, if our specialty is to survive and be credible, we must seek to meet the needs of our patients and our students. In most urban areas, family medicine has abandoned large parts of our patients’ care to the specialties of emergency medicine and obstetrics/gynecology.

From the rural perspective, it is impractical or fiscally impossible to recruit and maintain platoons of obstetricians and board-certified emergency medicine specialists to counties not located near a metropolitan area.^31,32 Family physicians, if properly trained, are the ideal physicians for nonmetropolitan practice.

Moreover, the current practice management curriculum in most family practice residencies is a do-it-yourself suicide kit where few physicians understand accountability measures for billing, collections, equipment, and human resources. They may have memorized the entire amino acid sequence for the human genome, but they don’t have the time to understand billing for Medicaid or the impact of providing a full range of services to their patients. What’s wrong with this picture?

FPs must adapt to serve their patients

The net result of the production of our graduates lacking technical skills is an overstocked urban job pool and a shortage of rural physicians. There are few 9-to-5 family practice jobs available in urban areas like Nashville and Memphis for limited generalists. On the other hand, there are jobs for every family physician willing to work after 5 P.M. This includes continuing care, urgent care, and middle-of-the-night hospital care. Procedural skills and hospital service predictably require “extra effort” and extra risk. Reimbursement policies continue to favor those physicians who assume these risks and provide these services.^33.34

Another result of following the path of least resistance (as reflected in nonprocedural family medicine is the decreasing student interest in family medicine.³⁵

Responsibility also rests with unskilled faculty who will not perform a broader scope of practice within the medical specialty of family medicine. There is personal risk for “being there” at the critical moment of procedural decisions. Students do not automatically shun this risk, but family medicine may be self-selecting for those who do.

Family physicians practicing in diverse geographic, social, and political environments will naturally adopt various diagnostic and therapeutic modalities in the service of their patients. It is not up to us to judge the appropriateness of those modalities except by the ultimate yardstick of the quality of the end result.

We are not advocating the addition of laparoscopic cholecystectomy to the “required” family medicine curriculum. However, we support the right of John Haynes to practice this skill and to teach it to others to the benefit of patients. The specialty that cannot provide training and credentials for its own members has been reproductively sterilized.^36,37 This is a unique market niche ideally suited for family medicine.^38,39

Procedurally trained family physicians represent the cutting edge of an emerging paradigm of care that includes ambulatory surgery, maternity care, cesarean section, and laparoscopy, particularly for patients in smaller communities and developing nations. We salute John Haynes and his co-authors for taking “the road less traveled.”

Corresponding author
Wm. MacMillan Rodney, MD, 6575 Black Thorne Cove, Memphis, TN 38119. E-mail: [email protected].

Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) —collectively known as “test charac-teristics” —are important ways to express the usefulness of diagnostic tests. The 2 x 2 tables from which these terms are derived are familiar to some physicians ( Table ).

Sensitivity is the “true positive rate,” equivalent to a/a+c. Specificity is the “true negative rate,” equivalent to d/b+d. PPV is the proportion of people with a positive test result who actually have the disease (a/a+b); NPV is the proportion of those with a negative result who do not have the disease (d/c+d).

Sensitivity and specificity are fixed for a particular type of test. PPV and NPV for a particular type of test depend upon the prevalence of a disease in a population. For example, though current screening tests for HIV have high sensitivity and specificity, the low prevalence of HIV in the general population cannot justify universal screening since the majority of positive tests would be falsely positive (ie, low PPV).

TABLE
2 x 2 table for diagnostic test results

How to Remember these Terms

Begin by assuming that you have 4 patients. For the first 2 you know only their disease status; for the last 2 patients you know only their test result.

You know your patient’s disease status:

1. Sensitivity: “I know my patient has the dis-ease. What is the chance that the test will show that my patient has it?”
2. Specificity: “I know my patient doesn’t have the disease. What is the chance that the test will show that my patient doesn’t have it?”
3. PPV: “I just got a positive test result back on my patient. What is the chance that my patient actually has the disease?”
4. For NPV: “I just got a negative test result back on my patient. What is the chance that my patient actually doesn’t have the disease?”

Keeping these 4 questions in mind as you run across these frequently used terms will help you interpret diagnostic tests accurately and efficiently, without having to think about more awkward 2 x 2 tables.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) —collectively known as “test charac-teristics” —are important ways to express the usefulness of diagnostic tests. The 2 x 2 tables from which these terms are derived are familiar to some physicians ( Table ).

Sensitivity is the “true positive rate,” equivalent to a/a+c. Specificity is the “true negative rate,” equivalent to d/b+d. PPV is the proportion of people with a positive test result who actually have the disease (a/a+b); NPV is the proportion of those with a negative result who do not have the disease (d/c+d).

Sensitivity and specificity are fixed for a particular type of test. PPV and NPV for a particular type of test depend upon the prevalence of a disease in a population. For example, though current screening tests for HIV have high sensitivity and specificity, the low prevalence of HIV in the general population cannot justify universal screening since the majority of positive tests would be falsely positive (ie, low PPV).

TABLE
2 x 2 table for diagnostic test results

How to Remember these Terms

Begin by assuming that you have 4 patients. For the first 2 you know only their disease status; for the last 2 patients you know only their test result.

You know your patient’s disease status:

1. Sensitivity: “I know my patient has the dis-ease. What is the chance that the test will show that my patient has it?”
2. Specificity: “I know my patient doesn’t have the disease. What is the chance that the test will show that my patient doesn’t have it?”
3. PPV: “I just got a positive test result back on my patient. What is the chance that my patient actually has the disease?”
4. For NPV: “I just got a negative test result back on my patient. What is the chance that my patient actually doesn’t have the disease?”

Keeping these 4 questions in mind as you run across these frequently used terms will help you interpret diagnostic tests accurately and efficiently, without having to think about more awkward 2 x 2 tables.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) —collectively known as “test charac-teristics” —are important ways to express the usefulness of diagnostic tests. The 2 x 2 tables from which these terms are derived are familiar to some physicians ( Table ).

Sensitivity is the “true positive rate,” equivalent to a/a+c. Specificity is the “true negative rate,” equivalent to d/b+d. PPV is the proportion of people with a positive test result who actually have the disease (a/a+b); NPV is the proportion of those with a negative result who do not have the disease (d/c+d).

Sensitivity and specificity are fixed for a particular type of test. PPV and NPV for a particular type of test depend upon the prevalence of a disease in a population. For example, though current screening tests for HIV have high sensitivity and specificity, the low prevalence of HIV in the general population cannot justify universal screening since the majority of positive tests would be falsely positive (ie, low PPV).

TABLE
2 x 2 table for diagnostic test results

How to Remember these Terms

Begin by assuming that you have 4 patients. For the first 2 you know only their disease status; for the last 2 patients you know only their test result.

You know your patient’s disease status:

1. Sensitivity: “I know my patient has the dis-ease. What is the chance that the test will show that my patient has it?”
2. Specificity: “I know my patient doesn’t have the disease. What is the chance that the test will show that my patient doesn’t have it?”
3. PPV: “I just got a positive test result back on my patient. What is the chance that my patient actually has the disease?”
4. For NPV: “I just got a negative test result back on my patient. What is the chance that my patient actually doesn’t have the disease?”

Keeping these 4 questions in mind as you run across these frequently used terms will help you interpret diagnostic tests accurately and efficiently, without having to think about more awkward 2 x 2 tables.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

For older people at increased risk of falling due to multiple predisposing risk factors, acute diseases and drug side effects are the most common precipitants for falls. Other individual and environmental factors identified here also cause falls, and their recognition can lead to quick diagnosis and remedy, and to careful supervision and environmental strategies that can prevent falls.

The problem in residential care facilities

Falls and their consequences—such as fractures and other injuries, fear of falling, impaired functions, and dependency—are serious health problems in the older population.¹ Older people living in residential care facilities and those receiving long-term institutional care seem particularly prone to falling and fractures caused by falls.^2-4

Almost half of all patients with hip fractures in Umeå, Sweden, during the 1980s and the 1990s lived in residential care facilities, although fewer than 10% of the elderly population lived in such accommodations.⁴ Falls among people aged 60 years and older have been estimated to account for one third of the total cost of medical treatment for all injuries in the Swedish population.⁵

Predisposing and precipitating factors for falls

Falls have a number of causes—both chronic predisposing factors and acute precipitants.

Chronic predisposing factors

Chronic predisposing factors increase the risk of a fall. The greater the number of predisposing factors, the greater the risk. Most research has focused on predisposing factors—diseases, previous falls, disorders of gait and balance, impaired neuromuscular function, and poor vision are rather well-known risk factors.⁶ Treatment with drugs—such as neuroleptics, benzodiazepines, analgesics, digitalis, steroids, diuretics, and antidepressants—are also risk factors for falls.^7-12 Given these predisposing factors, rather small changes in medical status or environment may then precipitate a fall.

In geriatric medicine textbooks, falls have commonly been regarded as a symptom of disease,¹³ but the evidence for this is supported by few studies.^14,15 External factors and environmental circumstances have been found to contribute to the risk of falls among the elderly, with or without injury, but have mostly been studied in the home environment.^16-18

Acute precipitating factors

Few studies have focused on precipitating factors for falls.^14,16 Several attempts to perform randomized fall prevention studies in residential care facilities have been unsuccessful in reducing the number of fallers, falls, and injuries.^19-23 However, they have not included prevention and treatment of such precipitating factors as acute diseases and drug side effects.

Aim of this study

This prospective cohort study aimed at identifying precipitating factors for falls among older people living in residential care facilities by analyzing the circumstances—related to the individual and to the environment—prevailing at the time of the fall.

Methods

The design of this study was a prospective cohort study with baseline assessments, a prospective follow-up for falls, post-fall assessments, and post-fall conferences.

Settings and participants

Residential care facilities in Sweden accommodate older people who are disabled because of cognitive or physical impairment and thus require supervision, functional support, or nursing care. Different settings may exist in the same facility or groups of facilities: senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia.

In senior citizens’ apartments, the residents live in private facilities with 1 or 2 rooms, a kitchen, and a lavatory. In the old people’s home and the group dwelling, the residents live in private rooms including a lavatory, and have their meals in a communal dining room. In all facilities, residents have 24-hour access to assistance with activities of daily living, household issues, and medical care.²⁴ In Sweden 8% of people aged 65 years and older live in such accommodations, according to statistical reports from the National Board of Health and Welfare in Sweden.

Residents of 5 facilities, including senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia, were asked to participate in the study. Informed consent was obtained from the patient or proxy. The study was approved by the Ethics Committee of the Faculty of Medicine at Umeå University.

Baseline assessments

All participants were assessed at the start of the study. Social and medical data (including medications) were collected from the participants, medical records, caregivers, and relatives. The Barthel activities of daily living (ADL) index was used to measure patients’ ability to function on their own.²⁵ Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Body mass index (BMI) was also measured.

Falls were recorded over 12 months or until participants died or moved. A fall was defined as any event in which the resident unintentionally came to rest on the floor regardless of cause; this included syncopal falls, falls resulting from acute disease or epileptic seizure, and unexplained falls after which the resident was found on the floor by staff. All drugs taken within 24 hours before a fall were documented.

This study was part of an intervention study targeting both general and resident-specific risk factors for falling. Interventions included staff education about falls, post-fall assessments and fall prevention, environmental modification, exercise programs, supply or repair of aids, review of drug regimens, hip protectors, post-fall problem-solving conferences, and staff guidance.²⁴

Though a large proportion of the residents had multiple risk factors predisposing them to falls, the focus of this study was the precipitating factors—ie, the circumstances prevailing at the time of the fall.

Follow-ups for falls

A report form developed from experiences in previous studies was used for post-fall evaluation. The first section of the form was structured with questions about the fall: date, time, activity, new symptoms, and external factors such as darkness, obstacles, footwear, and walking aids. The staff—licensed practical nurses and nurse’s aides–filled in this section.

The last 3 parts of the form were filled in after evaluation of possible causes of the fall, by the registered nurse of the residential care facility (the same day), the physician responsible for the residents, and a physiotherapist employed part-time in the project (on the same day if possible, but at least within the same week).

The post-fall assessments included interviews of the resident, the staff, and sometimes relatives, as well as a physical examination and laboratory tests when indicated. To prevent further falls, the physician, nurse, and physiotherapist conferred and determined the most probable explanation of the fall and took appropriate preventive measures when possible.

After data collection, the research study group (1 physiotherapist [JJ] and 2 physicians [YG and KK]) evaluated the documentation on each fall and formed a consensus about the most probable precipitating factor for each fall. In some cases where consensus was not reached, the majority decided the precipitating factor, or more than 1 factor was assigned to the fall.

Injuries were classified according to the 7-grade Abbreviated Injury Scale (AIS), where MAIS indicates the most serious injury connected with the incident.²⁶ The injuries in this study ranged from MAIS 0.5 to 3, from minor (eg, superficial wounds) to serious (eg, hip fractures).

Acute disease or symptoms of disease were regarded as a precipitating factor when symptoms or changes in the medical condition before that fall disappeared with treatment. For example, several urinary tract infections were detected after a fall. The resident could have been feeling dizzy, anxious, and weak at the knees prior to the fall. These symptoms disappeared after treatment of the infection and were in some cases validated as a precipitating factor since recurrent urinary tract infections resulted in more falls. Similarly, in cases when a drug was judged to have precipitated the fall, drug side effects from a newly prescribed drug were reported, and the symptoms disappeared after discontinuation of the drug treatment. Delirium was diagnosed according to DSM-IV criteria²⁷ by the physician of each residential care facility, and it was judged as a precipitating factor when the underlying cause of the delirium was unknown.

Statistical analyses

The groups of fallers and nonfallers were compared using the chi-square test, the Fisher’s exact test, the Student t test, and the Mann-Whitney U test when appropriate. Factors associated with being a faller in bivariate analyses were, after controlling for multicollinearity, included in logistic regression analyses to find factors independently associated with being a faller.

P values <.05 were regarded as statistically significant. The Statistical Package for the Social Sciences version 10.0 was used for all calculations.

Results

Twelve residents declined to participate. Thirteen died or moved before baseline assessments. Eventually 140 (70%) women and 59 men with a mean age of 82.4 years (SD ± 6.8; range, 65–97) were enrolled in the study after their own (or, in patients with dementia, their relatives’) informed consent had been obtained.

The clinical characteristics of the participants at inclusion can be seen in Table 1. One hundred thirteen (57%) residents sustained at least 1 fall during the 12 months of the study. Seventy-four of 113 (65%) fallers sustained at least 1 injury; 32% of the 482 falls resulted in an injury. Previous falls, impaired cognition and ADL ability, depression, delirium, treatment with antidepressants, and use of laxatives were associated with falling. A multiple logistic regression analysis revealed that falls within the last 6 months and treatment with antidepressants were the factors independently associated with falling (data not shown).

TABLE 1
Characteristics of the 199 residents at inclusion

Factors precipitating falls

The most probable precipitating factors for falls could be judged in 331 (68.7%; 95% confidence interval [CI], 64.6–72.8) of the 482 registered falls. In 297 falls, 1 factor was judged to be precipitating; in 28 falls, 2 factors; in 5 falls, 3 factors; and in 1 fall, 4 contributing factors were judged to be precipitating.

Disease. Acute disease or symptoms of disease, including exacerbations of chronic diseases and syncope, were judged to be precipitating factors in 186 (38.6%; 95% CI, 34.3–42.9) of all falls (Table 2). Thirty-eight of the total number of falls (7.9%; 95% CI, 5.9–9.9) were precipitated by infections, most often symptomatic urinary tract infections, and 11 (2.3%; 95% CI, 1.3–3.3) by acute stroke. Forty-eight falls (10.0%; 95% CI, 7.3–12.7) were precipitated by delirium. Seven residents, of whom 6 were known alcoholics, sustained 19 falls under the influence of alcohol.

Drugs. Drugs were judged to be a precipitating factor in 37 (7.7%; 95% CI, 5.7–9.7) falls (Table 3). Benzodiazepines or neuroleptics were involved in 32 of these 37 falls. Sleeping medicine given at the wrong time—too soon before the residents went to bed—resulted in 7 falls (in 7 residents).

In 7 of the falls precipitated by drugs, the judgment was that there had been an overdose (various combinations of benzodiazepines, dextropropoxyphene, propiomazine, levomepromazine [not available in the US], and carbamazepine) in 1 resident who had problems with addiction to drugs and alcohol. At the time of 1 of these falls this resident was also under the influence of alcohol. In the fall precipitated by antibiotics, the reason was an allergic reaction.

External factors. External factors precipitated 38 falls (7.9%; 95% CI, 5.9–9.9), most often in the form of obstacles (12 cases) or material defects (8 cases) (Table 4).

Thirty-four residents were using hip protectors (18 all day and night, 11 all day, and 5 some days). Hip protectors were judged to have precipitated 3 falls as they became stuck at the knees when the wearer was dressing, often after visiting the bathroom. In all 3 falls, the hip protectors were a precipitating factor in combination with usual clothing.

Other conditions. Other conditions, due both to the individual and the environment, were judged to precipitate 83 falls (17.2; 95% CI, 13.9–20.5) (Table 5). Errors of judgment/misinterpretation—eg, overestimation of one’s own ability, or forgetfulness by the resident—such as not calling for help when moving despite an inability to move without assistance, precipitated 34 falls.

Misuse of a walker precipitated 15 falls. Miscalculation, probably because of perceptual disturbances, such as missing a step when leaving a car or the chair when sitting down, precipitated 14 falls.

Mistakes made by the staff, such as leaving a resident alone on the toilet, forgetting to put on parts of a wheelchair, or turning off the light at night—all in disregard of agreements—lay behind 12 falls. A lack of adequate facilities caused 3 falls. Mistreatment by other residents resulted in 2 falls. Falling asleep in a chair, a state of exhaustion after an eye examination, a frightening nightmare, and an unexplained sudden loss of balance lead to 1 fall each.

TABLE 2
Acute diseases and symptoms of disease precipitating falls

TABLE 3
Acute drug side effects precipitating falls

TABLE 4
External factors precipitating falls

TABLE 5
Other conditions precipitating falls

Discussion

This study confirms that a large proportion of older people in residential care facilities suffer from falls and injuries. The most important predisposing factors for falls in this study were a history of previous falls and treatment with antidepressants, according to a logistic regression analysis that is supported in previous studies.²⁸ Major precipitating factors were acute diseases, drug side effects, external factors, and other conditions both related to the individual and the environment.

Acute diseases usually detectable

Acute diseases, often commonplace and treatable, seem to be important precipitating factors for falls in this population, and the risk-factor profile with increased susceptibility is probably one explanation for this. The 39% of the falls precipitated by acute disease or symptoms of disease is even higher than the proportion reported in earlier studies (9%–17%).^14,29

Delirium, here the most frequent precipitating symptom, is by definition usually a symptom of an underlying disease. However, it was frequently impossible to determine the underlying causes of the delirium, which is also true regarding other symptoms such as anxiety.

One explanation for the higher proportion of acute diseases as precipitating factors in this study is probably the accuracy with which the falls were followed up by 3 different professionals. Many of the most common diseases and symptoms of diseases precipitating falls should be possible to prevent or diagnose quickly to prevent falls.

Drugs: first-dose and dosage-increase complications

Drugs precipitated almost 8% of the falls, a proportion that seems to correspond to the results of previous studies.^14,29 Benzodiazepines and neuroleptics were not significantly associated with falls as predisposing factors in this study, opposite to what has been previously reported.³⁰

However, these drugs were important precipitating factors alone, in combination with each other or in combination with other drugs, and they accounted for 32 out of the 37 falls precipitated by drugs. These drugs have also previously been reported as important precipitating factors for falls among older people and should therefore be used with caution.³⁰

Sleeping medicine (eg, zopiclone [a benzodiazepine not available in the US], zolpidem, and flunitrazepam) given at the wrong time and thereby causing falls, indicates that individual dispensing of medicines could probably prevent some falls. This conclusion is supported by the fact that none of these 7 residents fell again, for the same reason, after adjustments to the dispensing of their medicine.

Drugs as precipitating factors were mainly related to first-dose problems, but also to side effects at dose escalations. Many drug side effects are delayed, sometimes by several weeks, and it can be difficult to state with certainty that there is a correlation between the fall and the drug. This could indicate an underestimation of drugs as precipitating factors for falls. No fall, for instance, was judged to be precipitated by antidepressants, which is surprising since antidepressants are a well known predisposing factor for falls among older people,^8,9,11,30 and a rather large proportion of the residents, especially of those who sustained a fall, had been prescribed antidepressants.

One explanation is probably the late onset of side effects with antidepressants; another possibility is that there may have been only a few new prescriptions during the study. Depression as well as use of antidepressants are well-known predisposing factors for falls. It is only the possible role of antidepressants as precipitating factors that is discussed here. In a previous study²⁸ we have distinguished between the depression and the treatment, showing antidepressants to be independently associated with falls.

Consequently, many of the symptoms described could be, and probably are, symptoms of diseases or drug side effects that are never diagnosed.

External factors

External factors were judged to precipitate almost 8% of the falls. In some studies, 35%–45% of falls are attributed to home hazards,^31,32 but case control studies have failed to find an association between environmental hazards and the occurrence of injurious or repeated falls in older people living in the community.^33,34

Furthermore, external factors seem less important as precipitating factors among frail older people in institutions.³⁵ Material defects and obstacles account, in this study, for the half of the external precipitating factors and it ought to be possible to prevent such falls to a greater extent.

Other conditions

Other conditions, such as errors of judgment/misinterpretation, miscalculation, and misuse of walkers by the residents are examples of conditions often related to the individual’s reduced cognitive capacity, which are often difficult to prevent. Concerning roller walkers, a more critical judgment and a better follow-up when placing one at a resident’s disposal could prevent falls, since a walker may even be a precipitating factor for falls in residents with dementia. Mistakes made by the staff and the lack of adequate facilities could be the result of anything from ignorance and carelessness to understaffing.

In addition, prevention of falls in people with cognitive impairment is probably best ensured through better supervision and—perhaps in some cases—by some kind of physical restraints, although some studies have shown that physical restraints can produce a higher risk for falls, especially injurious falls.³⁶ In the studied sample, only 20 (10%) residents had bed rails (7% of the fallers and 14% of the nonfallers), and 2 nonfallers were restrained by geribelts. No one had been prescribed restraints to prevent falls during the study. Instead, residents with a high risk of falling and sustaining hip fractures were offered hip protectors.

Conclusions

The evaluation of precipitating factors were made by 3 different professionals (nurses, physiotherapists, and physicians), all with experience in care of older people. Our opinion is that the cooperation of these different competencies have resulted in valid judgments regarding precipitant factors for the falls despite that the evaluation of a precipitant for a fall always includes some degree of subjectivity.

The careful follow-up of the falls allowed a decision to be made concerning the most probable precipitating factor (or factors) for the fall in more than two thirds of the incidents, despite the inclusion of a rather large proportion of cognitively impaired residents in the study material. The proportion of falls that could be judged was the same in the cognitively well functioning as in the cognitively impaired residents.

Intervention program significantly reduced the number of falls

This study was part of an intervention program that resulted in a significant reduction in the number of fallers, falls, and hip fractures.²⁴ The intervention program consisted of both general and resident-specific strategies: educating staff, modifying the environment, implementing exercise programs, supplying and repairing aids, reviewing drug regimens, providing free hip protectors, having post-fall problem-solving conferences and guiding staff.

These post-fall problem-solving conferences are what differs between this successful intervention study and other previously published randomized fall prevention studies in residential care,^19-23 which indicates that this might be an important fall prevention strategy.

However, this poses the greatest problem methodologically, since the follow-up of the falls led to an intervention to prevent further falls. This means that this study, if anything, underestimates the number of falls as well as precipitating factors for falls among older people in residential care.

Potential problems with this study

Postprandial hypotension has been reported to be an important precipitating factor for falls in older people³⁷ but was not assessed for in this study. It cannot be excluded that other possible precipitating factors for falls also can have been overlooked or under diagnosed such as syncope, especially in frail cognitively impaired residents.

Final thoughts

The cause of a fall in an older person is multifactorial including combinations of predisposing and precipitating factors often both related to the individual and the environment. An effective clinical strategy for risk assessment and management therefore must address both predisposing and precipitating factors.³⁸

By analogy with accident research in general we think that our focus and analysis of the fall in itself is one fruitful way to approach more effective prevention of this health problem in the older population. It also gives the opportunity to an individualized secondary prevention.

Acknowledgments

The authors acknowledge Staffan Eriksson, Mai Matson, Ellinor Nordin, Erik Rosendahl, Olov Sandberg, and Monica Östensson for their contribution to the data collection. Preliminary results were presented as a poster at the 17th congress of the International Association of Gerontology, Vancouver, Canada, July 2001. This study was financially supported by grants from the County Council of Västerbotten, the Federation of County Councils in Sweden, the Umeå University Foundation of Medical Research, the Gun and Bertil Stohnes Foundation, the Swedish Foundation for Healthcare Sciences and Allergy Research and Erik and Anne-Marie Detlof’s Foundation, Umeå University.

Corresponding author
Kristina Kallin, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, SE-901 87 Umeå, Sweden. E-mail: [email protected].

For older people at increased risk of falling due to multiple predisposing risk factors, acute diseases and drug side effects are the most common precipitants for falls. Other individual and environmental factors identified here also cause falls, and their recognition can lead to quick diagnosis and remedy, and to careful supervision and environmental strategies that can prevent falls.

The problem in residential care facilities

Falls and their consequences—such as fractures and other injuries, fear of falling, impaired functions, and dependency—are serious health problems in the older population.¹ Older people living in residential care facilities and those receiving long-term institutional care seem particularly prone to falling and fractures caused by falls.^2-4

Almost half of all patients with hip fractures in Umeå, Sweden, during the 1980s and the 1990s lived in residential care facilities, although fewer than 10% of the elderly population lived in such accommodations.⁴ Falls among people aged 60 years and older have been estimated to account for one third of the total cost of medical treatment for all injuries in the Swedish population.⁵

Predisposing and precipitating factors for falls

Falls have a number of causes—both chronic predisposing factors and acute precipitants.

Chronic predisposing factors

Chronic predisposing factors increase the risk of a fall. The greater the number of predisposing factors, the greater the risk. Most research has focused on predisposing factors—diseases, previous falls, disorders of gait and balance, impaired neuromuscular function, and poor vision are rather well-known risk factors.⁶ Treatment with drugs—such as neuroleptics, benzodiazepines, analgesics, digitalis, steroids, diuretics, and antidepressants—are also risk factors for falls.^7-12 Given these predisposing factors, rather small changes in medical status or environment may then precipitate a fall.

In geriatric medicine textbooks, falls have commonly been regarded as a symptom of disease,¹³ but the evidence for this is supported by few studies.^14,15 External factors and environmental circumstances have been found to contribute to the risk of falls among the elderly, with or without injury, but have mostly been studied in the home environment.^16-18

Acute precipitating factors

Few studies have focused on precipitating factors for falls.^14,16 Several attempts to perform randomized fall prevention studies in residential care facilities have been unsuccessful in reducing the number of fallers, falls, and injuries.^19-23 However, they have not included prevention and treatment of such precipitating factors as acute diseases and drug side effects.

Aim of this study

This prospective cohort study aimed at identifying precipitating factors for falls among older people living in residential care facilities by analyzing the circumstances—related to the individual and to the environment—prevailing at the time of the fall.

Methods

The design of this study was a prospective cohort study with baseline assessments, a prospective follow-up for falls, post-fall assessments, and post-fall conferences.

Settings and participants

Residential care facilities in Sweden accommodate older people who are disabled because of cognitive or physical impairment and thus require supervision, functional support, or nursing care. Different settings may exist in the same facility or groups of facilities: senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia.

In senior citizens’ apartments, the residents live in private facilities with 1 or 2 rooms, a kitchen, and a lavatory. In the old people’s home and the group dwelling, the residents live in private rooms including a lavatory, and have their meals in a communal dining room. In all facilities, residents have 24-hour access to assistance with activities of daily living, household issues, and medical care.²⁴ In Sweden 8% of people aged 65 years and older live in such accommodations, according to statistical reports from the National Board of Health and Welfare in Sweden.

Residents of 5 facilities, including senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia, were asked to participate in the study. Informed consent was obtained from the patient or proxy. The study was approved by the Ethics Committee of the Faculty of Medicine at Umeå University.

Baseline assessments

All participants were assessed at the start of the study. Social and medical data (including medications) were collected from the participants, medical records, caregivers, and relatives. The Barthel activities of daily living (ADL) index was used to measure patients’ ability to function on their own.²⁵ Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Body mass index (BMI) was also measured.

Falls were recorded over 12 months or until participants died or moved. A fall was defined as any event in which the resident unintentionally came to rest on the floor regardless of cause; this included syncopal falls, falls resulting from acute disease or epileptic seizure, and unexplained falls after which the resident was found on the floor by staff. All drugs taken within 24 hours before a fall were documented.

This study was part of an intervention study targeting both general and resident-specific risk factors for falling. Interventions included staff education about falls, post-fall assessments and fall prevention, environmental modification, exercise programs, supply or repair of aids, review of drug regimens, hip protectors, post-fall problem-solving conferences, and staff guidance.²⁴

Though a large proportion of the residents had multiple risk factors predisposing them to falls, the focus of this study was the precipitating factors—ie, the circumstances prevailing at the time of the fall.

Follow-ups for falls

A report form developed from experiences in previous studies was used for post-fall evaluation. The first section of the form was structured with questions about the fall: date, time, activity, new symptoms, and external factors such as darkness, obstacles, footwear, and walking aids. The staff—licensed practical nurses and nurse’s aides–filled in this section.

The last 3 parts of the form were filled in after evaluation of possible causes of the fall, by the registered nurse of the residential care facility (the same day), the physician responsible for the residents, and a physiotherapist employed part-time in the project (on the same day if possible, but at least within the same week).

The post-fall assessments included interviews of the resident, the staff, and sometimes relatives, as well as a physical examination and laboratory tests when indicated. To prevent further falls, the physician, nurse, and physiotherapist conferred and determined the most probable explanation of the fall and took appropriate preventive measures when possible.

After data collection, the research study group (1 physiotherapist [JJ] and 2 physicians [YG and KK]) evaluated the documentation on each fall and formed a consensus about the most probable precipitating factor for each fall. In some cases where consensus was not reached, the majority decided the precipitating factor, or more than 1 factor was assigned to the fall.

Injuries were classified according to the 7-grade Abbreviated Injury Scale (AIS), where MAIS indicates the most serious injury connected with the incident.²⁶ The injuries in this study ranged from MAIS 0.5 to 3, from minor (eg, superficial wounds) to serious (eg, hip fractures).

Acute disease or symptoms of disease were regarded as a precipitating factor when symptoms or changes in the medical condition before that fall disappeared with treatment. For example, several urinary tract infections were detected after a fall. The resident could have been feeling dizzy, anxious, and weak at the knees prior to the fall. These symptoms disappeared after treatment of the infection and were in some cases validated as a precipitating factor since recurrent urinary tract infections resulted in more falls. Similarly, in cases when a drug was judged to have precipitated the fall, drug side effects from a newly prescribed drug were reported, and the symptoms disappeared after discontinuation of the drug treatment. Delirium was diagnosed according to DSM-IV criteria²⁷ by the physician of each residential care facility, and it was judged as a precipitating factor when the underlying cause of the delirium was unknown.

Statistical analyses

The groups of fallers and nonfallers were compared using the chi-square test, the Fisher’s exact test, the Student t test, and the Mann-Whitney U test when appropriate. Factors associated with being a faller in bivariate analyses were, after controlling for multicollinearity, included in logistic regression analyses to find factors independently associated with being a faller.

P values <.05 were regarded as statistically significant. The Statistical Package for the Social Sciences version 10.0 was used for all calculations.

Results

Twelve residents declined to participate. Thirteen died or moved before baseline assessments. Eventually 140 (70%) women and 59 men with a mean age of 82.4 years (SD ± 6.8; range, 65–97) were enrolled in the study after their own (or, in patients with dementia, their relatives’) informed consent had been obtained.

The clinical characteristics of the participants at inclusion can be seen in Table 1. One hundred thirteen (57%) residents sustained at least 1 fall during the 12 months of the study. Seventy-four of 113 (65%) fallers sustained at least 1 injury; 32% of the 482 falls resulted in an injury. Previous falls, impaired cognition and ADL ability, depression, delirium, treatment with antidepressants, and use of laxatives were associated with falling. A multiple logistic regression analysis revealed that falls within the last 6 months and treatment with antidepressants were the factors independently associated with falling (data not shown).

TABLE 1
Characteristics of the 199 residents at inclusion

Factors precipitating falls

The most probable precipitating factors for falls could be judged in 331 (68.7%; 95% confidence interval [CI], 64.6–72.8) of the 482 registered falls. In 297 falls, 1 factor was judged to be precipitating; in 28 falls, 2 factors; in 5 falls, 3 factors; and in 1 fall, 4 contributing factors were judged to be precipitating.

Disease. Acute disease or symptoms of disease, including exacerbations of chronic diseases and syncope, were judged to be precipitating factors in 186 (38.6%; 95% CI, 34.3–42.9) of all falls (Table 2). Thirty-eight of the total number of falls (7.9%; 95% CI, 5.9–9.9) were precipitated by infections, most often symptomatic urinary tract infections, and 11 (2.3%; 95% CI, 1.3–3.3) by acute stroke. Forty-eight falls (10.0%; 95% CI, 7.3–12.7) were precipitated by delirium. Seven residents, of whom 6 were known alcoholics, sustained 19 falls under the influence of alcohol.

Drugs. Drugs were judged to be a precipitating factor in 37 (7.7%; 95% CI, 5.7–9.7) falls (Table 3). Benzodiazepines or neuroleptics were involved in 32 of these 37 falls. Sleeping medicine given at the wrong time—too soon before the residents went to bed—resulted in 7 falls (in 7 residents).

In 7 of the falls precipitated by drugs, the judgment was that there had been an overdose (various combinations of benzodiazepines, dextropropoxyphene, propiomazine, levomepromazine [not available in the US], and carbamazepine) in 1 resident who had problems with addiction to drugs and alcohol. At the time of 1 of these falls this resident was also under the influence of alcohol. In the fall precipitated by antibiotics, the reason was an allergic reaction.

External factors. External factors precipitated 38 falls (7.9%; 95% CI, 5.9–9.9), most often in the form of obstacles (12 cases) or material defects (8 cases) (Table 4).

Thirty-four residents were using hip protectors (18 all day and night, 11 all day, and 5 some days). Hip protectors were judged to have precipitated 3 falls as they became stuck at the knees when the wearer was dressing, often after visiting the bathroom. In all 3 falls, the hip protectors were a precipitating factor in combination with usual clothing.

Other conditions. Other conditions, due both to the individual and the environment, were judged to precipitate 83 falls (17.2; 95% CI, 13.9–20.5) (Table 5). Errors of judgment/misinterpretation—eg, overestimation of one’s own ability, or forgetfulness by the resident—such as not calling for help when moving despite an inability to move without assistance, precipitated 34 falls.

Misuse of a walker precipitated 15 falls. Miscalculation, probably because of perceptual disturbances, such as missing a step when leaving a car or the chair when sitting down, precipitated 14 falls.

Mistakes made by the staff, such as leaving a resident alone on the toilet, forgetting to put on parts of a wheelchair, or turning off the light at night—all in disregard of agreements—lay behind 12 falls. A lack of adequate facilities caused 3 falls. Mistreatment by other residents resulted in 2 falls. Falling asleep in a chair, a state of exhaustion after an eye examination, a frightening nightmare, and an unexplained sudden loss of balance lead to 1 fall each.

TABLE 2
Acute diseases and symptoms of disease precipitating falls

TABLE 3
Acute drug side effects precipitating falls

TABLE 4
External factors precipitating falls

TABLE 5
Other conditions precipitating falls

Discussion

This study confirms that a large proportion of older people in residential care facilities suffer from falls and injuries. The most important predisposing factors for falls in this study were a history of previous falls and treatment with antidepressants, according to a logistic regression analysis that is supported in previous studies.²⁸ Major precipitating factors were acute diseases, drug side effects, external factors, and other conditions both related to the individual and the environment.

Acute diseases usually detectable

Acute diseases, often commonplace and treatable, seem to be important precipitating factors for falls in this population, and the risk-factor profile with increased susceptibility is probably one explanation for this. The 39% of the falls precipitated by acute disease or symptoms of disease is even higher than the proportion reported in earlier studies (9%–17%).^14,29

Delirium, here the most frequent precipitating symptom, is by definition usually a symptom of an underlying disease. However, it was frequently impossible to determine the underlying causes of the delirium, which is also true regarding other symptoms such as anxiety.

One explanation for the higher proportion of acute diseases as precipitating factors in this study is probably the accuracy with which the falls were followed up by 3 different professionals. Many of the most common diseases and symptoms of diseases precipitating falls should be possible to prevent or diagnose quickly to prevent falls.

Drugs: first-dose and dosage-increase complications

Drugs precipitated almost 8% of the falls, a proportion that seems to correspond to the results of previous studies.^14,29 Benzodiazepines and neuroleptics were not significantly associated with falls as predisposing factors in this study, opposite to what has been previously reported.³⁰

However, these drugs were important precipitating factors alone, in combination with each other or in combination with other drugs, and they accounted for 32 out of the 37 falls precipitated by drugs. These drugs have also previously been reported as important precipitating factors for falls among older people and should therefore be used with caution.³⁰

Sleeping medicine (eg, zopiclone [a benzodiazepine not available in the US], zolpidem, and flunitrazepam) given at the wrong time and thereby causing falls, indicates that individual dispensing of medicines could probably prevent some falls. This conclusion is supported by the fact that none of these 7 residents fell again, for the same reason, after adjustments to the dispensing of their medicine.

Drugs as precipitating factors were mainly related to first-dose problems, but also to side effects at dose escalations. Many drug side effects are delayed, sometimes by several weeks, and it can be difficult to state with certainty that there is a correlation between the fall and the drug. This could indicate an underestimation of drugs as precipitating factors for falls. No fall, for instance, was judged to be precipitated by antidepressants, which is surprising since antidepressants are a well known predisposing factor for falls among older people,^8,9,11,30 and a rather large proportion of the residents, especially of those who sustained a fall, had been prescribed antidepressants.

One explanation is probably the late onset of side effects with antidepressants; another possibility is that there may have been only a few new prescriptions during the study. Depression as well as use of antidepressants are well-known predisposing factors for falls. It is only the possible role of antidepressants as precipitating factors that is discussed here. In a previous study²⁸ we have distinguished between the depression and the treatment, showing antidepressants to be independently associated with falls.

Consequently, many of the symptoms described could be, and probably are, symptoms of diseases or drug side effects that are never diagnosed.

External factors

External factors were judged to precipitate almost 8% of the falls. In some studies, 35%–45% of falls are attributed to home hazards,^31,32 but case control studies have failed to find an association between environmental hazards and the occurrence of injurious or repeated falls in older people living in the community.^33,34

Furthermore, external factors seem less important as precipitating factors among frail older people in institutions.³⁵ Material defects and obstacles account, in this study, for the half of the external precipitating factors and it ought to be possible to prevent such falls to a greater extent.

Other conditions

Other conditions, such as errors of judgment/misinterpretation, miscalculation, and misuse of walkers by the residents are examples of conditions often related to the individual’s reduced cognitive capacity, which are often difficult to prevent. Concerning roller walkers, a more critical judgment and a better follow-up when placing one at a resident’s disposal could prevent falls, since a walker may even be a precipitating factor for falls in residents with dementia. Mistakes made by the staff and the lack of adequate facilities could be the result of anything from ignorance and carelessness to understaffing.

In addition, prevention of falls in people with cognitive impairment is probably best ensured through better supervision and—perhaps in some cases—by some kind of physical restraints, although some studies have shown that physical restraints can produce a higher risk for falls, especially injurious falls.³⁶ In the studied sample, only 20 (10%) residents had bed rails (7% of the fallers and 14% of the nonfallers), and 2 nonfallers were restrained by geribelts. No one had been prescribed restraints to prevent falls during the study. Instead, residents with a high risk of falling and sustaining hip fractures were offered hip protectors.

Conclusions

The evaluation of precipitating factors were made by 3 different professionals (nurses, physiotherapists, and physicians), all with experience in care of older people. Our opinion is that the cooperation of these different competencies have resulted in valid judgments regarding precipitant factors for the falls despite that the evaluation of a precipitant for a fall always includes some degree of subjectivity.

The careful follow-up of the falls allowed a decision to be made concerning the most probable precipitating factor (or factors) for the fall in more than two thirds of the incidents, despite the inclusion of a rather large proportion of cognitively impaired residents in the study material. The proportion of falls that could be judged was the same in the cognitively well functioning as in the cognitively impaired residents.

Intervention program significantly reduced the number of falls

This study was part of an intervention program that resulted in a significant reduction in the number of fallers, falls, and hip fractures.²⁴ The intervention program consisted of both general and resident-specific strategies: educating staff, modifying the environment, implementing exercise programs, supplying and repairing aids, reviewing drug regimens, providing free hip protectors, having post-fall problem-solving conferences and guiding staff.

These post-fall problem-solving conferences are what differs between this successful intervention study and other previously published randomized fall prevention studies in residential care,^19-23 which indicates that this might be an important fall prevention strategy.

However, this poses the greatest problem methodologically, since the follow-up of the falls led to an intervention to prevent further falls. This means that this study, if anything, underestimates the number of falls as well as precipitating factors for falls among older people in residential care.

Potential problems with this study

Postprandial hypotension has been reported to be an important precipitating factor for falls in older people³⁷ but was not assessed for in this study. It cannot be excluded that other possible precipitating factors for falls also can have been overlooked or under diagnosed such as syncope, especially in frail cognitively impaired residents.

Final thoughts

The cause of a fall in an older person is multifactorial including combinations of predisposing and precipitating factors often both related to the individual and the environment. An effective clinical strategy for risk assessment and management therefore must address both predisposing and precipitating factors.³⁸

By analogy with accident research in general we think that our focus and analysis of the fall in itself is one fruitful way to approach more effective prevention of this health problem in the older population. It also gives the opportunity to an individualized secondary prevention.

Acknowledgments

The authors acknowledge Staffan Eriksson, Mai Matson, Ellinor Nordin, Erik Rosendahl, Olov Sandberg, and Monica Östensson for their contribution to the data collection. Preliminary results were presented as a poster at the 17th congress of the International Association of Gerontology, Vancouver, Canada, July 2001. This study was financially supported by grants from the County Council of Västerbotten, the Federation of County Councils in Sweden, the Umeå University Foundation of Medical Research, the Gun and Bertil Stohnes Foundation, the Swedish Foundation for Healthcare Sciences and Allergy Research and Erik and Anne-Marie Detlof’s Foundation, Umeå University.

Corresponding author
Kristina Kallin, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, SE-901 87 Umeå, Sweden. E-mail: [email protected].

For older people at increased risk of falling due to multiple predisposing risk factors, acute diseases and drug side effects are the most common precipitants for falls. Other individual and environmental factors identified here also cause falls, and their recognition can lead to quick diagnosis and remedy, and to careful supervision and environmental strategies that can prevent falls.

The problem in residential care facilities

Falls and their consequences—such as fractures and other injuries, fear of falling, impaired functions, and dependency—are serious health problems in the older population.¹ Older people living in residential care facilities and those receiving long-term institutional care seem particularly prone to falling and fractures caused by falls.^2-4

Almost half of all patients with hip fractures in Umeå, Sweden, during the 1980s and the 1990s lived in residential care facilities, although fewer than 10% of the elderly population lived in such accommodations.⁴ Falls among people aged 60 years and older have been estimated to account for one third of the total cost of medical treatment for all injuries in the Swedish population.⁵

Predisposing and precipitating factors for falls

Falls have a number of causes—both chronic predisposing factors and acute precipitants.

Chronic predisposing factors

Chronic predisposing factors increase the risk of a fall. The greater the number of predisposing factors, the greater the risk. Most research has focused on predisposing factors—diseases, previous falls, disorders of gait and balance, impaired neuromuscular function, and poor vision are rather well-known risk factors.⁶ Treatment with drugs—such as neuroleptics, benzodiazepines, analgesics, digitalis, steroids, diuretics, and antidepressants—are also risk factors for falls.^7-12 Given these predisposing factors, rather small changes in medical status or environment may then precipitate a fall.

In geriatric medicine textbooks, falls have commonly been regarded as a symptom of disease,¹³ but the evidence for this is supported by few studies.^14,15 External factors and environmental circumstances have been found to contribute to the risk of falls among the elderly, with or without injury, but have mostly been studied in the home environment.^16-18

Acute precipitating factors

Few studies have focused on precipitating factors for falls.^14,16 Several attempts to perform randomized fall prevention studies in residential care facilities have been unsuccessful in reducing the number of fallers, falls, and injuries.^19-23 However, they have not included prevention and treatment of such precipitating factors as acute diseases and drug side effects.

Aim of this study

This prospective cohort study aimed at identifying precipitating factors for falls among older people living in residential care facilities by analyzing the circumstances—related to the individual and to the environment—prevailing at the time of the fall.

Methods

The design of this study was a prospective cohort study with baseline assessments, a prospective follow-up for falls, post-fall assessments, and post-fall conferences.

Settings and participants

Residential care facilities in Sweden accommodate older people who are disabled because of cognitive or physical impairment and thus require supervision, functional support, or nursing care. Different settings may exist in the same facility or groups of facilities: senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia.

In senior citizens’ apartments, the residents live in private facilities with 1 or 2 rooms, a kitchen, and a lavatory. In the old people’s home and the group dwelling, the residents live in private rooms including a lavatory, and have their meals in a communal dining room. In all facilities, residents have 24-hour access to assistance with activities of daily living, household issues, and medical care.²⁴ In Sweden 8% of people aged 65 years and older live in such accommodations, according to statistical reports from the National Board of Health and Welfare in Sweden.

Residents of 5 facilities, including senior citizens’ apartments, old people’s homes, and group dwellings for people with dementia, were asked to participate in the study. Informed consent was obtained from the patient or proxy. The study was approved by the Ethics Committee of the Faculty of Medicine at Umeå University.

Baseline assessments

All participants were assessed at the start of the study. Social and medical data (including medications) were collected from the participants, medical records, caregivers, and relatives. The Barthel activities of daily living (ADL) index was used to measure patients’ ability to function on their own.²⁵ Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Body mass index (BMI) was also measured.

Falls were recorded over 12 months or until participants died or moved. A fall was defined as any event in which the resident unintentionally came to rest on the floor regardless of cause; this included syncopal falls, falls resulting from acute disease or epileptic seizure, and unexplained falls after which the resident was found on the floor by staff. All drugs taken within 24 hours before a fall were documented.

This study was part of an intervention study targeting both general and resident-specific risk factors for falling. Interventions included staff education about falls, post-fall assessments and fall prevention, environmental modification, exercise programs, supply or repair of aids, review of drug regimens, hip protectors, post-fall problem-solving conferences, and staff guidance.²⁴

Though a large proportion of the residents had multiple risk factors predisposing them to falls, the focus of this study was the precipitating factors—ie, the circumstances prevailing at the time of the fall.

Follow-ups for falls

A report form developed from experiences in previous studies was used for post-fall evaluation. The first section of the form was structured with questions about the fall: date, time, activity, new symptoms, and external factors such as darkness, obstacles, footwear, and walking aids. The staff—licensed practical nurses and nurse’s aides–filled in this section.

The last 3 parts of the form were filled in after evaluation of possible causes of the fall, by the registered nurse of the residential care facility (the same day), the physician responsible for the residents, and a physiotherapist employed part-time in the project (on the same day if possible, but at least within the same week).

The post-fall assessments included interviews of the resident, the staff, and sometimes relatives, as well as a physical examination and laboratory tests when indicated. To prevent further falls, the physician, nurse, and physiotherapist conferred and determined the most probable explanation of the fall and took appropriate preventive measures when possible.

After data collection, the research study group (1 physiotherapist [JJ] and 2 physicians [YG and KK]) evaluated the documentation on each fall and formed a consensus about the most probable precipitating factor for each fall. In some cases where consensus was not reached, the majority decided the precipitating factor, or more than 1 factor was assigned to the fall.

Injuries were classified according to the 7-grade Abbreviated Injury Scale (AIS), where MAIS indicates the most serious injury connected with the incident.²⁶ The injuries in this study ranged from MAIS 0.5 to 3, from minor (eg, superficial wounds) to serious (eg, hip fractures).

Acute disease or symptoms of disease were regarded as a precipitating factor when symptoms or changes in the medical condition before that fall disappeared with treatment. For example, several urinary tract infections were detected after a fall. The resident could have been feeling dizzy, anxious, and weak at the knees prior to the fall. These symptoms disappeared after treatment of the infection and were in some cases validated as a precipitating factor since recurrent urinary tract infections resulted in more falls. Similarly, in cases when a drug was judged to have precipitated the fall, drug side effects from a newly prescribed drug were reported, and the symptoms disappeared after discontinuation of the drug treatment. Delirium was diagnosed according to DSM-IV criteria²⁷ by the physician of each residential care facility, and it was judged as a precipitating factor when the underlying cause of the delirium was unknown.

Statistical analyses

The groups of fallers and nonfallers were compared using the chi-square test, the Fisher’s exact test, the Student t test, and the Mann-Whitney U test when appropriate. Factors associated with being a faller in bivariate analyses were, after controlling for multicollinearity, included in logistic regression analyses to find factors independently associated with being a faller.

P values <.05 were regarded as statistically significant. The Statistical Package for the Social Sciences version 10.0 was used for all calculations.

Results

Twelve residents declined to participate. Thirteen died or moved before baseline assessments. Eventually 140 (70%) women and 59 men with a mean age of 82.4 years (SD ± 6.8; range, 65–97) were enrolled in the study after their own (or, in patients with dementia, their relatives’) informed consent had been obtained.

The clinical characteristics of the participants at inclusion can be seen in Table 1. One hundred thirteen (57%) residents sustained at least 1 fall during the 12 months of the study. Seventy-four of 113 (65%) fallers sustained at least 1 injury; 32% of the 482 falls resulted in an injury. Previous falls, impaired cognition and ADL ability, depression, delirium, treatment with antidepressants, and use of laxatives were associated with falling. A multiple logistic regression analysis revealed that falls within the last 6 months and treatment with antidepressants were the factors independently associated with falling (data not shown).

TABLE 1
Characteristics of the 199 residents at inclusion

Factors precipitating falls

The most probable precipitating factors for falls could be judged in 331 (68.7%; 95% confidence interval [CI], 64.6–72.8) of the 482 registered falls. In 297 falls, 1 factor was judged to be precipitating; in 28 falls, 2 factors; in 5 falls, 3 factors; and in 1 fall, 4 contributing factors were judged to be precipitating.

Disease. Acute disease or symptoms of disease, including exacerbations of chronic diseases and syncope, were judged to be precipitating factors in 186 (38.6%; 95% CI, 34.3–42.9) of all falls (Table 2). Thirty-eight of the total number of falls (7.9%; 95% CI, 5.9–9.9) were precipitated by infections, most often symptomatic urinary tract infections, and 11 (2.3%; 95% CI, 1.3–3.3) by acute stroke. Forty-eight falls (10.0%; 95% CI, 7.3–12.7) were precipitated by delirium. Seven residents, of whom 6 were known alcoholics, sustained 19 falls under the influence of alcohol.

Drugs. Drugs were judged to be a precipitating factor in 37 (7.7%; 95% CI, 5.7–9.7) falls (Table 3). Benzodiazepines or neuroleptics were involved in 32 of these 37 falls. Sleeping medicine given at the wrong time—too soon before the residents went to bed—resulted in 7 falls (in 7 residents).

In 7 of the falls precipitated by drugs, the judgment was that there had been an overdose (various combinations of benzodiazepines, dextropropoxyphene, propiomazine, levomepromazine [not available in the US], and carbamazepine) in 1 resident who had problems with addiction to drugs and alcohol. At the time of 1 of these falls this resident was also under the influence of alcohol. In the fall precipitated by antibiotics, the reason was an allergic reaction.

External factors. External factors precipitated 38 falls (7.9%; 95% CI, 5.9–9.9), most often in the form of obstacles (12 cases) or material defects (8 cases) (Table 4).

Thirty-four residents were using hip protectors (18 all day and night, 11 all day, and 5 some days). Hip protectors were judged to have precipitated 3 falls as they became stuck at the knees when the wearer was dressing, often after visiting the bathroom. In all 3 falls, the hip protectors were a precipitating factor in combination with usual clothing.

Other conditions. Other conditions, due both to the individual and the environment, were judged to precipitate 83 falls (17.2; 95% CI, 13.9–20.5) (Table 5). Errors of judgment/misinterpretation—eg, overestimation of one’s own ability, or forgetfulness by the resident—such as not calling for help when moving despite an inability to move without assistance, precipitated 34 falls.

Misuse of a walker precipitated 15 falls. Miscalculation, probably because of perceptual disturbances, such as missing a step when leaving a car or the chair when sitting down, precipitated 14 falls.

Mistakes made by the staff, such as leaving a resident alone on the toilet, forgetting to put on parts of a wheelchair, or turning off the light at night—all in disregard of agreements—lay behind 12 falls. A lack of adequate facilities caused 3 falls. Mistreatment by other residents resulted in 2 falls. Falling asleep in a chair, a state of exhaustion after an eye examination, a frightening nightmare, and an unexplained sudden loss of balance lead to 1 fall each.

TABLE 2
Acute diseases and symptoms of disease precipitating falls

TABLE 3
Acute drug side effects precipitating falls

TABLE 4
External factors precipitating falls

TABLE 5
Other conditions precipitating falls

Discussion

This study confirms that a large proportion of older people in residential care facilities suffer from falls and injuries. The most important predisposing factors for falls in this study were a history of previous falls and treatment with antidepressants, according to a logistic regression analysis that is supported in previous studies.²⁸ Major precipitating factors were acute diseases, drug side effects, external factors, and other conditions both related to the individual and the environment.

Acute diseases usually detectable

Acute diseases, often commonplace and treatable, seem to be important precipitating factors for falls in this population, and the risk-factor profile with increased susceptibility is probably one explanation for this. The 39% of the falls precipitated by acute disease or symptoms of disease is even higher than the proportion reported in earlier studies (9%–17%).^14,29

Delirium, here the most frequent precipitating symptom, is by definition usually a symptom of an underlying disease. However, it was frequently impossible to determine the underlying causes of the delirium, which is also true regarding other symptoms such as anxiety.

One explanation for the higher proportion of acute diseases as precipitating factors in this study is probably the accuracy with which the falls were followed up by 3 different professionals. Many of the most common diseases and symptoms of diseases precipitating falls should be possible to prevent or diagnose quickly to prevent falls.

Drugs: first-dose and dosage-increase complications

Drugs precipitated almost 8% of the falls, a proportion that seems to correspond to the results of previous studies.^14,29 Benzodiazepines and neuroleptics were not significantly associated with falls as predisposing factors in this study, opposite to what has been previously reported.³⁰

However, these drugs were important precipitating factors alone, in combination with each other or in combination with other drugs, and they accounted for 32 out of the 37 falls precipitated by drugs. These drugs have also previously been reported as important precipitating factors for falls among older people and should therefore be used with caution.³⁰

Sleeping medicine (eg, zopiclone [a benzodiazepine not available in the US], zolpidem, and flunitrazepam) given at the wrong time and thereby causing falls, indicates that individual dispensing of medicines could probably prevent some falls. This conclusion is supported by the fact that none of these 7 residents fell again, for the same reason, after adjustments to the dispensing of their medicine.

Drugs as precipitating factors were mainly related to first-dose problems, but also to side effects at dose escalations. Many drug side effects are delayed, sometimes by several weeks, and it can be difficult to state with certainty that there is a correlation between the fall and the drug. This could indicate an underestimation of drugs as precipitating factors for falls. No fall, for instance, was judged to be precipitated by antidepressants, which is surprising since antidepressants are a well known predisposing factor for falls among older people,^8,9,11,30 and a rather large proportion of the residents, especially of those who sustained a fall, had been prescribed antidepressants.

One explanation is probably the late onset of side effects with antidepressants; another possibility is that there may have been only a few new prescriptions during the study. Depression as well as use of antidepressants are well-known predisposing factors for falls. It is only the possible role of antidepressants as precipitating factors that is discussed here. In a previous study²⁸ we have distinguished between the depression and the treatment, showing antidepressants to be independently associated with falls.

Consequently, many of the symptoms described could be, and probably are, symptoms of diseases or drug side effects that are never diagnosed.

External factors

External factors were judged to precipitate almost 8% of the falls. In some studies, 35%–45% of falls are attributed to home hazards,^31,32 but case control studies have failed to find an association between environmental hazards and the occurrence of injurious or repeated falls in older people living in the community.^33,34

Furthermore, external factors seem less important as precipitating factors among frail older people in institutions.³⁵ Material defects and obstacles account, in this study, for the half of the external precipitating factors and it ought to be possible to prevent such falls to a greater extent.

Other conditions

Other conditions, such as errors of judgment/misinterpretation, miscalculation, and misuse of walkers by the residents are examples of conditions often related to the individual’s reduced cognitive capacity, which are often difficult to prevent. Concerning roller walkers, a more critical judgment and a better follow-up when placing one at a resident’s disposal could prevent falls, since a walker may even be a precipitating factor for falls in residents with dementia. Mistakes made by the staff and the lack of adequate facilities could be the result of anything from ignorance and carelessness to understaffing.

In addition, prevention of falls in people with cognitive impairment is probably best ensured through better supervision and—perhaps in some cases—by some kind of physical restraints, although some studies have shown that physical restraints can produce a higher risk for falls, especially injurious falls.³⁶ In the studied sample, only 20 (10%) residents had bed rails (7% of the fallers and 14% of the nonfallers), and 2 nonfallers were restrained by geribelts. No one had been prescribed restraints to prevent falls during the study. Instead, residents with a high risk of falling and sustaining hip fractures were offered hip protectors.

Conclusions

The evaluation of precipitating factors were made by 3 different professionals (nurses, physiotherapists, and physicians), all with experience in care of older people. Our opinion is that the cooperation of these different competencies have resulted in valid judgments regarding precipitant factors for the falls despite that the evaluation of a precipitant for a fall always includes some degree of subjectivity.

The careful follow-up of the falls allowed a decision to be made concerning the most probable precipitating factor (or factors) for the fall in more than two thirds of the incidents, despite the inclusion of a rather large proportion of cognitively impaired residents in the study material. The proportion of falls that could be judged was the same in the cognitively well functioning as in the cognitively impaired residents.

Intervention program significantly reduced the number of falls

This study was part of an intervention program that resulted in a significant reduction in the number of fallers, falls, and hip fractures.²⁴ The intervention program consisted of both general and resident-specific strategies: educating staff, modifying the environment, implementing exercise programs, supplying and repairing aids, reviewing drug regimens, providing free hip protectors, having post-fall problem-solving conferences and guiding staff.

These post-fall problem-solving conferences are what differs between this successful intervention study and other previously published randomized fall prevention studies in residential care,^19-23 which indicates that this might be an important fall prevention strategy.

However, this poses the greatest problem methodologically, since the follow-up of the falls led to an intervention to prevent further falls. This means that this study, if anything, underestimates the number of falls as well as precipitating factors for falls among older people in residential care.

Potential problems with this study

Postprandial hypotension has been reported to be an important precipitating factor for falls in older people³⁷ but was not assessed for in this study. It cannot be excluded that other possible precipitating factors for falls also can have been overlooked or under diagnosed such as syncope, especially in frail cognitively impaired residents.

Final thoughts

The cause of a fall in an older person is multifactorial including combinations of predisposing and precipitating factors often both related to the individual and the environment. An effective clinical strategy for risk assessment and management therefore must address both predisposing and precipitating factors.³⁸

By analogy with accident research in general we think that our focus and analysis of the fall in itself is one fruitful way to approach more effective prevention of this health problem in the older population. It also gives the opportunity to an individualized secondary prevention.

Acknowledgments

The authors acknowledge Staffan Eriksson, Mai Matson, Ellinor Nordin, Erik Rosendahl, Olov Sandberg, and Monica Östensson for their contribution to the data collection. Preliminary results were presented as a poster at the 17th congress of the International Association of Gerontology, Vancouver, Canada, July 2001. This study was financially supported by grants from the County Council of Västerbotten, the Federation of County Councils in Sweden, the Umeå University Foundation of Medical Research, the Gun and Bertil Stohnes Foundation, the Swedish Foundation for Healthcare Sciences and Allergy Research and Erik and Anne-Marie Detlof’s Foundation, Umeå University.

Corresponding author
Kristina Kallin, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University, SE-901 87 Umeå, Sweden. E-mail: [email protected].

The question “How statistically significant are the results of a study?” can be answered in several ways. For example, the difference in mean blood-pressure lowering effect between a new drug and placebo from a specific study can be expressed as:

Difference=8.5 mm Hg; P=.03

However, the true effect of the drug is unlikely to be exactly 8.5 mm Hg—if the study were repeated, the results would be somewhat different. The variation is not explained by the P value. The P value is prone to misinterpretation, as will be explained in a future Language of Evidence. It tells us only that a difference is significant; it says nothing about its magnitude or precision.

Confidence intervals are a better alternative. Consider the difference above expressed as a confidence interval:

Difference=8.5 mm Hg; 95% CI, 6.3–10.8 or, graphically:

The probability of obtaining a result of 8.5 mm Hg, assuming the true value is not within the interval of 6.3–10.8 mm Hg, is 5% or less. In other words, one wouldn’t get the result above very often if the true value is outside the interval. This interpretation seems convoluted. It is easier to think of it this way: “The true value for the difference is most likely between 6.3 and 10.8. It is unlikely to be outside of this interval.”

3 Important principles

1. The wider a confidence interval, the less precise the estimate. Precision depends upon sample size. Therefore, the larger the sample size of a study, the narrower the confidence interval and the better the estimate. In the example above, a similar study with a much larger sample size may yield a narrower difference: 8.5 mm Hg; 95% CI, 7.4–8.9.
2. The 90% (or lower) confidence interval for an estimate is narrower than the 95% confidence interval; a 99% confidence interval is wider. This makes sense, since we are surer that a true value lies between 2 widely separated numbers than 2 more narrowly separated numbers.
3. If the confidence interval includes “no difference”(in this case, zero change in blood pressure), the corresponding Pvalue must be >.05. “No difference” for a result expressed as a subtraction is zero; for a result expressed as a ratio (such as an absolute difference or a relative risk), it would be 1. It is important to keep this difference in mind when interpreting confidence intervals.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

The question “How statistically significant are the results of a study?” can be answered in several ways. For example, the difference in mean blood-pressure lowering effect between a new drug and placebo from a specific study can be expressed as:

Difference=8.5 mm Hg; P=.03

However, the true effect of the drug is unlikely to be exactly 8.5 mm Hg—if the study were repeated, the results would be somewhat different. The variation is not explained by the P value. The P value is prone to misinterpretation, as will be explained in a future Language of Evidence. It tells us only that a difference is significant; it says nothing about its magnitude or precision.

Confidence intervals are a better alternative. Consider the difference above expressed as a confidence interval:

Difference=8.5 mm Hg; 95% CI, 6.3–10.8 or, graphically:

The probability of obtaining a result of 8.5 mm Hg, assuming the true value is not within the interval of 6.3–10.8 mm Hg, is 5% or less. In other words, one wouldn’t get the result above very often if the true value is outside the interval. This interpretation seems convoluted. It is easier to think of it this way: “The true value for the difference is most likely between 6.3 and 10.8. It is unlikely to be outside of this interval.”

3 Important principles

1. The wider a confidence interval, the less precise the estimate. Precision depends upon sample size. Therefore, the larger the sample size of a study, the narrower the confidence interval and the better the estimate. In the example above, a similar study with a much larger sample size may yield a narrower difference: 8.5 mm Hg; 95% CI, 7.4–8.9.
2. The 90% (or lower) confidence interval for an estimate is narrower than the 95% confidence interval; a 99% confidence interval is wider. This makes sense, since we are surer that a true value lies between 2 widely separated numbers than 2 more narrowly separated numbers.
3. If the confidence interval includes “no difference”(in this case, zero change in blood pressure), the corresponding Pvalue must be >.05. “No difference” for a result expressed as a subtraction is zero; for a result expressed as a ratio (such as an absolute difference or a relative risk), it would be 1. It is important to keep this difference in mind when interpreting confidence intervals.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

The question “How statistically significant are the results of a study?” can be answered in several ways. For example, the difference in mean blood-pressure lowering effect between a new drug and placebo from a specific study can be expressed as:

Difference=8.5 mm Hg; P=.03

However, the true effect of the drug is unlikely to be exactly 8.5 mm Hg—if the study were repeated, the results would be somewhat different. The variation is not explained by the P value. The P value is prone to misinterpretation, as will be explained in a future Language of Evidence. It tells us only that a difference is significant; it says nothing about its magnitude or precision.

Confidence intervals are a better alternative. Consider the difference above expressed as a confidence interval:

Difference=8.5 mm Hg; 95% CI, 6.3–10.8 or, graphically:

The probability of obtaining a result of 8.5 mm Hg, assuming the true value is not within the interval of 6.3–10.8 mm Hg, is 5% or less. In other words, one wouldn’t get the result above very often if the true value is outside the interval. This interpretation seems convoluted. It is easier to think of it this way: “The true value for the difference is most likely between 6.3 and 10.8. It is unlikely to be outside of this interval.”

3 Important principles

1. The wider a confidence interval, the less precise the estimate. Precision depends upon sample size. Therefore, the larger the sample size of a study, the narrower the confidence interval and the better the estimate. In the example above, a similar study with a much larger sample size may yield a narrower difference: 8.5 mm Hg; 95% CI, 7.4–8.9.
2. The 90% (or lower) confidence interval for an estimate is narrower than the 95% confidence interval; a 99% confidence interval is wider. This makes sense, since we are surer that a true value lies between 2 widely separated numbers than 2 more narrowly separated numbers.
3. If the confidence interval includes “no difference”(in this case, zero change in blood pressure), the corresponding Pvalue must be >.05. “No difference” for a result expressed as a subtraction is zero; for a result expressed as a ratio (such as an absolute difference or a relative risk), it would be 1. It is important to keep this difference in mind when interpreting confidence intervals.

Correspondence
Goutham Rao, MD, 3518 Fifth Avenue, Pittsburgh, PA 15261. E-mail: [email protected].

Hundreds of relevant studies of new or existing therapies are published each year. Interpreting the results in a way that is useful to both you and your patients is an important skill.

Consider the recently published Heart Protection Study,¹ which assessed the effect of simvastatin on specific cardiovascular outcomes and mortality by comparing it with placebo among 20,536 adults with pre-existing cardiovascular disease. Table 1 summarizes the effect of simvastatin, 40 mg once daily, on all-cause mortality after 5 years.

The proportion of patients in the simvastatin group who died was 1328/10,269 or 0.129 (12.9%); the proportion of the placebo group who died was 1507/10,267 or 0.147 (14.7%). The evidence suggests simvastatin is superior in reducing mortality. But how significant is the difference?

One way to translate these results into a more useful form is to determine the number needed to treat (NNT). The NNT in this case refers to the number of people one would need to treat with simvastatin to prevent 1 death. The first step is to determine the absolute risk reduction (ARR), which is simply the difference in the proportion of outcomes in the two treatment groups. In this case: ARR = 0.147 – 0.129 = 0.018.

The NNT is simply the inverse of the ARR. In this case NNT = 1/0.018 = 56. Therefore, 56 people with cardiovascular disease need to be treated with simvastatin to prevent 1 death in 5 years.

Is this reasonable? There is no absolutely correct answer. An appropriate NNT depends on the risks and benefits of treatment. A higher NNT is tolerable even with significant adverse effects if the treatment prevents a serious outcome such as heart disease or death. Migraine, by contrast, is not life-threatening. Treating 56 migraine sufferers to cure a single headache is unreasonable. The NNT for treatment of migraine with subcutaneous sumatriptan vs placebo is about 2.²

TABLE 1

Effects of simvastatin on all-cause mortality

Hundreds of relevant studies of new or existing therapies are published each year. Interpreting the results in a way that is useful to both you and your patients is an important skill.

Consider the recently published Heart Protection Study,¹ which assessed the effect of simvastatin on specific cardiovascular outcomes and mortality by comparing it with placebo among 20,536 adults with pre-existing cardiovascular disease. Table 1 summarizes the effect of simvastatin, 40 mg once daily, on all-cause mortality after 5 years.

The proportion of patients in the simvastatin group who died was 1328/10,269 or 0.129 (12.9%); the proportion of the placebo group who died was 1507/10,267 or 0.147 (14.7%). The evidence suggests simvastatin is superior in reducing mortality. But how significant is the difference?

One way to translate these results into a more useful form is to determine the number needed to treat (NNT). The NNT in this case refers to the number of people one would need to treat with simvastatin to prevent 1 death. The first step is to determine the absolute risk reduction (ARR), which is simply the difference in the proportion of outcomes in the two treatment groups. In this case: ARR = 0.147 – 0.129 = 0.018.

The NNT is simply the inverse of the ARR. In this case NNT = 1/0.018 = 56. Therefore, 56 people with cardiovascular disease need to be treated with simvastatin to prevent 1 death in 5 years.

Is this reasonable? There is no absolutely correct answer. An appropriate NNT depends on the risks and benefits of treatment. A higher NNT is tolerable even with significant adverse effects if the treatment prevents a serious outcome such as heart disease or death. Migraine, by contrast, is not life-threatening. Treating 56 migraine sufferers to cure a single headache is unreasonable. The NNT for treatment of migraine with subcutaneous sumatriptan vs placebo is about 2.²

TABLE 1

Effects of simvastatin on all-cause mortality

Hundreds of relevant studies of new or existing therapies are published each year. Interpreting the results in a way that is useful to both you and your patients is an important skill.

Consider the recently published Heart Protection Study,¹ which assessed the effect of simvastatin on specific cardiovascular outcomes and mortality by comparing it with placebo among 20,536 adults with pre-existing cardiovascular disease. Table 1 summarizes the effect of simvastatin, 40 mg once daily, on all-cause mortality after 5 years.

The proportion of patients in the simvastatin group who died was 1328/10,269 or 0.129 (12.9%); the proportion of the placebo group who died was 1507/10,267 or 0.147 (14.7%). The evidence suggests simvastatin is superior in reducing mortality. But how significant is the difference?

One way to translate these results into a more useful form is to determine the number needed to treat (NNT). The NNT in this case refers to the number of people one would need to treat with simvastatin to prevent 1 death. The first step is to determine the absolute risk reduction (ARR), which is simply the difference in the proportion of outcomes in the two treatment groups. In this case: ARR = 0.147 – 0.129 = 0.018.

The NNT is simply the inverse of the ARR. In this case NNT = 1/0.018 = 56. Therefore, 56 people with cardiovascular disease need to be treated with simvastatin to prevent 1 death in 5 years.

Is this reasonable? There is no absolutely correct answer. An appropriate NNT depends on the risks and benefits of treatment. A higher NNT is tolerable even with significant adverse effects if the treatment prevents a serious outcome such as heart disease or death. Migraine, by contrast, is not life-threatening. Treating 56 migraine sufferers to cure a single headache is unreasonable. The NNT for treatment of migraine with subcutaneous sumatriptan vs placebo is about 2.²

TABLE 1

Effects of simvastatin on all-cause mortality