Roughly 14 Million Americans Have Undiagnosed COPD

NEW ORLEANS – The most likely place to look for missed cases of chronic obstructive pulmonary disease – and they exist in abundance – is among women younger than age 65.

Chronic obstructive pulmonary disease, the fourth leading cause of death in the United States, is far and away the most widely underdiagnosed serious illness. The best available prevalence data on COPD come from the NHANES III (National Health and Nutrition Examination Survey III), which included spirometric testing in a proportionate sample of the U.S. population.

Extrapolating from those data, roughly 12 million Americans carry the diagnosis of COPD, and another 12 million have evidence of impaired lung function consistent with COPD but remain undiagnosed. Of those 12 million undiagnosed individuals, NHANES III data indicate that roughly a third have clinically relevant COPD warranting application of treatment guidelines, according to Dr. Fernando J. Martinez, professor of internal medicine and director of pulmonary diagnostic services at the University of Michigan, Ann Arbor.

He added that the latest data from NHANES IV, now under review, bump those estimates up to roughly 14 million patients with diagnosed COPD, and an equal number with undiagnosed COPD.

The NHANES III data showed that 70% of individuals with undiagnosed COPD are younger than age 65. Other studies point to a marked sex discrepancy in misdiagnosis. In one landmark study, investigators presented American and Canadian primary care physicians with a classic clinical scenario for COPD (that is, a patient with a strong smoking history, progressive shortness of breath, and chronic cough with morning sputum production). Half the time, investigators identified this hypothetical patient as male, the other half female. Physicians diagnosed COPD 58% of the time when the patient was male, but in only 42% of cases when the otherwise identical hypothetical patient was female (Chest 2001;119:1691-5).

This sex discrepancy in COPD diagnosis has been replicated in similar studies conducted in Spain and Israel, Dr. Martinez added.

Interestingly, the first diagnostic test most participating primary care physicians indicated they would order for this hypothetical patient was a chest x-ray, which Dr. Martinez dismissed as a "terrible" tool for diagnosing COPD. Spirometry, which is in fact the diagnostic test for COPD, would have been ordered initially by only 22% of the physicians.

The pulmonologist stressed that even though spirometry is the diagnostic test for airflow obstruction, three major sets of guidelines released within the past year uniformly emphasize that its use should be restricted to patients with respiratory symptoms. Using spirometry alone as a screening test results in substantial overdiagnosis.

The recent guidelines he referred to are the latest update from the Global Initiative for Chronic Obstructive Lung Disease, which Dr. Martinez coauthored; the joint American College of Physicians/American College of Chest Physicians/American Thoracic Society/European Respiratory Society guidelines (Ann. Intern. Med. 2011;155:179-91); and the U.K. National Institute for Health and Clinical Excellence guideline.

Spirometry continues to be greatly underutilized in primary care medicine, perhaps in part because some insurers are unwilling to pay for the test in the office setting, insisting instead that it be performed in a specialized pulmonary clinic. That policy is destined for the scrap heap, Dr. Martinez predicted. In the meantime, primary care physicians need to realize that spirometry "is remarkably easy – you only need to know two numbers to be able to do it and interpret it properly," he said.

In the study that identified sex bias in COPD diagnosis, classic COPD symptoms in women were misdiagnosed most frequently as asthma. That’s a crucial mistake, because the first-choice treatments for these two common respiratory diseases are "diametrically opposite," Dr. Martinez observed.

"In asthma, you use inhaled corticosteroids up front as first-line therapy. That’s not the case in COPD. In COPD you use a LABA [long-acting beta agonist] up front, and you add an inhaled corticosteroid to reduce the exacerbation rate in people at increased risk based on a history of two or more exacerbations in the past year," he explained.

All of the latest guidelines emphasize exacerbation reduction as a key component of COPD management. Exacerbations accelerate disease progression by worsening lung function and symptoms, and they drive up costs as well.

The National Heart, Lung, and Blood Institute is interested in developing a novel, practical means of screening the general population for COPD in primary care physicians’ offices. Toward that end, the institute recently awarded a large research grant to a team of investigators that includes Dr. Martinez. He said that while he and his coworkers are still in the brainstorming stage, they are drawn to a staged approach involving a very brief questionnaire, in-office measurement of peak expiratory flow via a pocket spirometer, followed by diagnostic-quality spirometry when indicated.

Polls of busy general internists and family physicians indicate that if this screening questionnaire is more than four questions long, they won’t use it. So, hypothetically, Dr. Martinez said, a three-item questionnaire might consist of something along these lines: How old are you? (Epidemiologic data indicate COPD risk rises at about age 40.) How much do you smoke? (COPD risk begins climbing with a lifetime history of just 100 cigarettes, a mere five packs.) And, do you have symptoms?

Dr. Martinez would like to incorporate in-office peak expiratory flow measurement using a pocket spirometer into the screening tool in light of the findings of a recent study in which he was a principal investigator.

This study of 5,761 patients demonstrated that it’s rare to find severe airflow obstruction in an individual whose FEV₁ is at least 60% of the predicted value (Chest 2011 Dec. 22 [Epub ahead of print; PMID 22194590]).

"A peak flow measurement has very good negative predictive value. That could be a useful part of a screening instrument that’s going to need to be very practical," he observed.

Dr. Martinez reported that he serves as a consultant to Actelion, Almirall, AstraZeneca, Bayer, Forest, GlaxoSmithKline, Ikaria, MedImmune, Merck, Novartis, Nycomed, Pearl, and Pfizer.

NEW ORLEANS – The most likely place to look for missed cases of chronic obstructive pulmonary disease – and they exist in abundance – is among women younger than age 65.

Chronic obstructive pulmonary disease, the fourth leading cause of death in the United States, is far and away the most widely underdiagnosed serious illness. The best available prevalence data on COPD come from the NHANES III (National Health and Nutrition Examination Survey III), which included spirometric testing in a proportionate sample of the U.S. population.

Extrapolating from those data, roughly 12 million Americans carry the diagnosis of COPD, and another 12 million have evidence of impaired lung function consistent with COPD but remain undiagnosed. Of those 12 million undiagnosed individuals, NHANES III data indicate that roughly a third have clinically relevant COPD warranting application of treatment guidelines, according to Dr. Fernando J. Martinez, professor of internal medicine and director of pulmonary diagnostic services at the University of Michigan, Ann Arbor.

He added that the latest data from NHANES IV, now under review, bump those estimates up to roughly 14 million patients with diagnosed COPD, and an equal number with undiagnosed COPD.

The NHANES III data showed that 70% of individuals with undiagnosed COPD are younger than age 65. Other studies point to a marked sex discrepancy in misdiagnosis. In one landmark study, investigators presented American and Canadian primary care physicians with a classic clinical scenario for COPD (that is, a patient with a strong smoking history, progressive shortness of breath, and chronic cough with morning sputum production). Half the time, investigators identified this hypothetical patient as male, the other half female. Physicians diagnosed COPD 58% of the time when the patient was male, but in only 42% of cases when the otherwise identical hypothetical patient was female (Chest 2001;119:1691-5).

This sex discrepancy in COPD diagnosis has been replicated in similar studies conducted in Spain and Israel, Dr. Martinez added.

Interestingly, the first diagnostic test most participating primary care physicians indicated they would order for this hypothetical patient was a chest x-ray, which Dr. Martinez dismissed as a "terrible" tool for diagnosing COPD. Spirometry, which is in fact the diagnostic test for COPD, would have been ordered initially by only 22% of the physicians.

The pulmonologist stressed that even though spirometry is the diagnostic test for airflow obstruction, three major sets of guidelines released within the past year uniformly emphasize that its use should be restricted to patients with respiratory symptoms. Using spirometry alone as a screening test results in substantial overdiagnosis.

The recent guidelines he referred to are the latest update from the Global Initiative for Chronic Obstructive Lung Disease, which Dr. Martinez coauthored; the joint American College of Physicians/American College of Chest Physicians/American Thoracic Society/European Respiratory Society guidelines (Ann. Intern. Med. 2011;155:179-91); and the U.K. National Institute for Health and Clinical Excellence guideline.

Spirometry continues to be greatly underutilized in primary care medicine, perhaps in part because some insurers are unwilling to pay for the test in the office setting, insisting instead that it be performed in a specialized pulmonary clinic. That policy is destined for the scrap heap, Dr. Martinez predicted. In the meantime, primary care physicians need to realize that spirometry "is remarkably easy – you only need to know two numbers to be able to do it and interpret it properly," he said.

In the study that identified sex bias in COPD diagnosis, classic COPD symptoms in women were misdiagnosed most frequently as asthma. That’s a crucial mistake, because the first-choice treatments for these two common respiratory diseases are "diametrically opposite," Dr. Martinez observed.

"In asthma, you use inhaled corticosteroids up front as first-line therapy. That’s not the case in COPD. In COPD you use a LABA [long-acting beta agonist] up front, and you add an inhaled corticosteroid to reduce the exacerbation rate in people at increased risk based on a history of two or more exacerbations in the past year," he explained.

All of the latest guidelines emphasize exacerbation reduction as a key component of COPD management. Exacerbations accelerate disease progression by worsening lung function and symptoms, and they drive up costs as well.

The National Heart, Lung, and Blood Institute is interested in developing a novel, practical means of screening the general population for COPD in primary care physicians’ offices. Toward that end, the institute recently awarded a large research grant to a team of investigators that includes Dr. Martinez. He said that while he and his coworkers are still in the brainstorming stage, they are drawn to a staged approach involving a very brief questionnaire, in-office measurement of peak expiratory flow via a pocket spirometer, followed by diagnostic-quality spirometry when indicated.

Polls of busy general internists and family physicians indicate that if this screening questionnaire is more than four questions long, they won’t use it. So, hypothetically, Dr. Martinez said, a three-item questionnaire might consist of something along these lines: How old are you? (Epidemiologic data indicate COPD risk rises at about age 40.) How much do you smoke? (COPD risk begins climbing with a lifetime history of just 100 cigarettes, a mere five packs.) And, do you have symptoms?

Dr. Martinez would like to incorporate in-office peak expiratory flow measurement using a pocket spirometer into the screening tool in light of the findings of a recent study in which he was a principal investigator.

This study of 5,761 patients demonstrated that it’s rare to find severe airflow obstruction in an individual whose FEV₁ is at least 60% of the predicted value (Chest 2011 Dec. 22 [Epub ahead of print; PMID 22194590]).

"A peak flow measurement has very good negative predictive value. That could be a useful part of a screening instrument that’s going to need to be very practical," he observed.

Dr. Martinez reported that he serves as a consultant to Actelion, Almirall, AstraZeneca, Bayer, Forest, GlaxoSmithKline, Ikaria, MedImmune, Merck, Novartis, Nycomed, Pearl, and Pfizer.

NEW ORLEANS – The most likely place to look for missed cases of chronic obstructive pulmonary disease – and they exist in abundance – is among women younger than age 65.

Chronic obstructive pulmonary disease, the fourth leading cause of death in the United States, is far and away the most widely underdiagnosed serious illness. The best available prevalence data on COPD come from the NHANES III (National Health and Nutrition Examination Survey III), which included spirometric testing in a proportionate sample of the U.S. population.

Extrapolating from those data, roughly 12 million Americans carry the diagnosis of COPD, and another 12 million have evidence of impaired lung function consistent with COPD but remain undiagnosed. Of those 12 million undiagnosed individuals, NHANES III data indicate that roughly a third have clinically relevant COPD warranting application of treatment guidelines, according to Dr. Fernando J. Martinez, professor of internal medicine and director of pulmonary diagnostic services at the University of Michigan, Ann Arbor.

He added that the latest data from NHANES IV, now under review, bump those estimates up to roughly 14 million patients with diagnosed COPD, and an equal number with undiagnosed COPD.

The NHANES III data showed that 70% of individuals with undiagnosed COPD are younger than age 65. Other studies point to a marked sex discrepancy in misdiagnosis. In one landmark study, investigators presented American and Canadian primary care physicians with a classic clinical scenario for COPD (that is, a patient with a strong smoking history, progressive shortness of breath, and chronic cough with morning sputum production). Half the time, investigators identified this hypothetical patient as male, the other half female. Physicians diagnosed COPD 58% of the time when the patient was male, but in only 42% of cases when the otherwise identical hypothetical patient was female (Chest 2001;119:1691-5).

This sex discrepancy in COPD diagnosis has been replicated in similar studies conducted in Spain and Israel, Dr. Martinez added.

Interestingly, the first diagnostic test most participating primary care physicians indicated they would order for this hypothetical patient was a chest x-ray, which Dr. Martinez dismissed as a "terrible" tool for diagnosing COPD. Spirometry, which is in fact the diagnostic test for COPD, would have been ordered initially by only 22% of the physicians.

The pulmonologist stressed that even though spirometry is the diagnostic test for airflow obstruction, three major sets of guidelines released within the past year uniformly emphasize that its use should be restricted to patients with respiratory symptoms. Using spirometry alone as a screening test results in substantial overdiagnosis.

The recent guidelines he referred to are the latest update from the Global Initiative for Chronic Obstructive Lung Disease, which Dr. Martinez coauthored; the joint American College of Physicians/American College of Chest Physicians/American Thoracic Society/European Respiratory Society guidelines (Ann. Intern. Med. 2011;155:179-91); and the U.K. National Institute for Health and Clinical Excellence guideline.

Spirometry continues to be greatly underutilized in primary care medicine, perhaps in part because some insurers are unwilling to pay for the test in the office setting, insisting instead that it be performed in a specialized pulmonary clinic. That policy is destined for the scrap heap, Dr. Martinez predicted. In the meantime, primary care physicians need to realize that spirometry "is remarkably easy – you only need to know two numbers to be able to do it and interpret it properly," he said.

In the study that identified sex bias in COPD diagnosis, classic COPD symptoms in women were misdiagnosed most frequently as asthma. That’s a crucial mistake, because the first-choice treatments for these two common respiratory diseases are "diametrically opposite," Dr. Martinez observed.

"In asthma, you use inhaled corticosteroids up front as first-line therapy. That’s not the case in COPD. In COPD you use a LABA [long-acting beta agonist] up front, and you add an inhaled corticosteroid to reduce the exacerbation rate in people at increased risk based on a history of two or more exacerbations in the past year," he explained.

All of the latest guidelines emphasize exacerbation reduction as a key component of COPD management. Exacerbations accelerate disease progression by worsening lung function and symptoms, and they drive up costs as well.

The National Heart, Lung, and Blood Institute is interested in developing a novel, practical means of screening the general population for COPD in primary care physicians’ offices. Toward that end, the institute recently awarded a large research grant to a team of investigators that includes Dr. Martinez. He said that while he and his coworkers are still in the brainstorming stage, they are drawn to a staged approach involving a very brief questionnaire, in-office measurement of peak expiratory flow via a pocket spirometer, followed by diagnostic-quality spirometry when indicated.

Polls of busy general internists and family physicians indicate that if this screening questionnaire is more than four questions long, they won’t use it. So, hypothetically, Dr. Martinez said, a three-item questionnaire might consist of something along these lines: How old are you? (Epidemiologic data indicate COPD risk rises at about age 40.) How much do you smoke? (COPD risk begins climbing with a lifetime history of just 100 cigarettes, a mere five packs.) And, do you have symptoms?

Dr. Martinez would like to incorporate in-office peak expiratory flow measurement using a pocket spirometer into the screening tool in light of the findings of a recent study in which he was a principal investigator.

This study of 5,761 patients demonstrated that it’s rare to find severe airflow obstruction in an individual whose FEV₁ is at least 60% of the predicted value (Chest 2011 Dec. 22 [Epub ahead of print; PMID 22194590]).

"A peak flow measurement has very good negative predictive value. That could be a useful part of a screening instrument that’s going to need to be very practical," he observed.

Dr. Martinez reported that he serves as a consultant to Actelion, Almirall, AstraZeneca, Bayer, Forest, GlaxoSmithKline, Ikaria, MedImmune, Merck, Novartis, Nycomed, Pearl, and Pfizer.