Does reducing smoking in the home protect children from the effects of second-hand smoke?

Evidence summary

Parent education reduces clinic visits for asthmatic children

A 2001 trial randomized 81 families with a smoking parent and an asthmatic child between 3 and 12 years of age to 3 sessions of behavioral and educational counseling or usual care at an outpatient asthma clinic.¹ Parental education included information on second-hand smoke, basic asthma education, and feedback about urine cotinine levels (a marker of nicotine absorption). Behavioral counseling focused on reducing second-hand smoke exposure by caregivers.

The education group had a significantly reduced risk of 2 or more asthma-related clinic visits in the following 12 months compared with usual care (odds ratio=0.32; P=.03; number needed to treat=5). No significant decrease was noted in mean urine cotinine levels between groups (adjusted mean difference=-0.38 ng/mg favoring education; P=.26).

A similar trial that measured changes in urine cotinine randomized 91 families with a smoking parent and an asthmatic child into 3 groups:²

• A control group received usual care (regular office visits at an asthma clinic and medication management)
• A monitoring group used a parental smoking diary and a children’s asthma symptom diary
• A counseling group received 5 counseling sessions and also kept diaries. An environmental monitor in the home was used to assess exposure to secondhand smoke.

In the counseling group, 21.4% of patients (6 of 28) maintained 0% exposure throughout the 30-month trial period compared with 3.6% and 3.8% in the monitoring and control groups, respectively (P<.05 for comparison of counseling group to monitoring and control).

Banning indoor smoking sharply cuts nicotine exposure

No data are available on education about second-hand smoke in families with nonasthmatic children. However, strong evidence suggests that smoking outside the house reduces exposure generally.

A 2003 cross-sectional survey of 164 households in the United Kingdom with at least 1 smoking parent and 1 bottle-fed infant looked for a correlation between strategies to reduce second-hand smoke and urine cotinine-to-creatinine ratios in the infants.³ Parents were classified into 3 groups according to whether they maintained a strict ban on smoking in the home, a less strict ban (smoking at home but not near the infant), or no ban.

The mean infant urinary cotinine-to-creatinine ratio was 2.43 in the no-ban group and 2.61 in the less-strict ban group (difference not significant). The combined mean for these 2 groups—2.58—was significantly higher than the mean of 1.26 in the strictest group (P<.001).

A later study recruited a convenience sample of 49 interested families with a smoking mother and a nonbreastfeeding infant between 2 and 12 months of age.⁴ Families were classified by smoking history into one of 3 groups: nonsmoking households, smoking households where efforts were made to limit smoke exposure, and smoking households where no efforts were made to limit exposure. Urine samples were obtained 3 times over 1 week. Urine cotinine levels in infants averaged 0.33 ng/mL in nonsmoking households, 2.47 ng/mL in smoking households with limited exposure, and 15.47 ng/mL in smoking households with unlimited exposure (P<.001 for all comparisons).

A case-control study that recruited families with asthmatic and nonasthmatic children assessed the effectiveness of parental behaviors to reduce second-hand smoke in 182 households with 1 smoking parent and a child between 6 and 12 years of age.⁵ Researchers measured room air nicotine and salivary cotinine concentrations.

The nicotine levels on children’s belts and in their bedrooms and the family room were approximately 3 log units lower in houses with strict smoking bans compared with households with any degree of indoor smoking (P<.0001). Similarly, salivary cotinine levels were approximately 4 log units lower in children of households with indoor smoking bans (P<.0001).

Recommendations

The United States Preventive Services Task Force (USPSTF) strongly recommends that physicians help all smoking adults to quit.⁶ The American Academy of Family Physicians endorses the USPSTF position and further advises that smoking parents be counseled about the health effects of environmental tobacco smoke on their children.⁷

The American Academy of Pediatrics⁸ and the Veterans Administration⁹ recommend urging parents to stop smoking to prevent serious health implications for their children; they further encourage pediatric clinicians to offer parents advice on quitting in order to limit children’s exposure to second-hand smoke.

Evidence summary

Parent education reduces clinic visits for asthmatic children

A 2001 trial randomized 81 families with a smoking parent and an asthmatic child between 3 and 12 years of age to 3 sessions of behavioral and educational counseling or usual care at an outpatient asthma clinic.¹ Parental education included information on second-hand smoke, basic asthma education, and feedback about urine cotinine levels (a marker of nicotine absorption). Behavioral counseling focused on reducing second-hand smoke exposure by caregivers.

The education group had a significantly reduced risk of 2 or more asthma-related clinic visits in the following 12 months compared with usual care (odds ratio=0.32; P=.03; number needed to treat=5). No significant decrease was noted in mean urine cotinine levels between groups (adjusted mean difference=-0.38 ng/mg favoring education; P=.26).

A similar trial that measured changes in urine cotinine randomized 91 families with a smoking parent and an asthmatic child into 3 groups:²

• A control group received usual care (regular office visits at an asthma clinic and medication management)
• A monitoring group used a parental smoking diary and a children’s asthma symptom diary
• A counseling group received 5 counseling sessions and also kept diaries. An environmental monitor in the home was used to assess exposure to secondhand smoke.

In the counseling group, 21.4% of patients (6 of 28) maintained 0% exposure throughout the 30-month trial period compared with 3.6% and 3.8% in the monitoring and control groups, respectively (P<.05 for comparison of counseling group to monitoring and control).

Banning indoor smoking sharply cuts nicotine exposure

No data are available on education about second-hand smoke in families with nonasthmatic children. However, strong evidence suggests that smoking outside the house reduces exposure generally.

A 2003 cross-sectional survey of 164 households in the United Kingdom with at least 1 smoking parent and 1 bottle-fed infant looked for a correlation between strategies to reduce second-hand smoke and urine cotinine-to-creatinine ratios in the infants.³ Parents were classified into 3 groups according to whether they maintained a strict ban on smoking in the home, a less strict ban (smoking at home but not near the infant), or no ban.

The mean infant urinary cotinine-to-creatinine ratio was 2.43 in the no-ban group and 2.61 in the less-strict ban group (difference not significant). The combined mean for these 2 groups—2.58—was significantly higher than the mean of 1.26 in the strictest group (P<.001).

A later study recruited a convenience sample of 49 interested families with a smoking mother and a nonbreastfeeding infant between 2 and 12 months of age.⁴ Families were classified by smoking history into one of 3 groups: nonsmoking households, smoking households where efforts were made to limit smoke exposure, and smoking households where no efforts were made to limit exposure. Urine samples were obtained 3 times over 1 week. Urine cotinine levels in infants averaged 0.33 ng/mL in nonsmoking households, 2.47 ng/mL in smoking households with limited exposure, and 15.47 ng/mL in smoking households with unlimited exposure (P<.001 for all comparisons).

A case-control study that recruited families with asthmatic and nonasthmatic children assessed the effectiveness of parental behaviors to reduce second-hand smoke in 182 households with 1 smoking parent and a child between 6 and 12 years of age.⁵ Researchers measured room air nicotine and salivary cotinine concentrations.

The nicotine levels on children’s belts and in their bedrooms and the family room were approximately 3 log units lower in houses with strict smoking bans compared with households with any degree of indoor smoking (P<.0001). Similarly, salivary cotinine levels were approximately 4 log units lower in children of households with indoor smoking bans (P<.0001).

Recommendations

The United States Preventive Services Task Force (USPSTF) strongly recommends that physicians help all smoking adults to quit.⁶ The American Academy of Family Physicians endorses the USPSTF position and further advises that smoking parents be counseled about the health effects of environmental tobacco smoke on their children.⁷

The American Academy of Pediatrics⁸ and the Veterans Administration⁹ recommend urging parents to stop smoking to prevent serious health implications for their children; they further encourage pediatric clinicians to offer parents advice on quitting in order to limit children’s exposure to second-hand smoke.

Evidence summary

Parent education reduces clinic visits for asthmatic children

A 2001 trial randomized 81 families with a smoking parent and an asthmatic child between 3 and 12 years of age to 3 sessions of behavioral and educational counseling or usual care at an outpatient asthma clinic.¹ Parental education included information on second-hand smoke, basic asthma education, and feedback about urine cotinine levels (a marker of nicotine absorption). Behavioral counseling focused on reducing second-hand smoke exposure by caregivers.

The education group had a significantly reduced risk of 2 or more asthma-related clinic visits in the following 12 months compared with usual care (odds ratio=0.32; P=.03; number needed to treat=5). No significant decrease was noted in mean urine cotinine levels between groups (adjusted mean difference=-0.38 ng/mg favoring education; P=.26).

A similar trial that measured changes in urine cotinine randomized 91 families with a smoking parent and an asthmatic child into 3 groups:²

• A control group received usual care (regular office visits at an asthma clinic and medication management)
• A monitoring group used a parental smoking diary and a children’s asthma symptom diary
• A counseling group received 5 counseling sessions and also kept diaries. An environmental monitor in the home was used to assess exposure to secondhand smoke.

In the counseling group, 21.4% of patients (6 of 28) maintained 0% exposure throughout the 30-month trial period compared with 3.6% and 3.8% in the monitoring and control groups, respectively (P<.05 for comparison of counseling group to monitoring and control).

Banning indoor smoking sharply cuts nicotine exposure

No data are available on education about second-hand smoke in families with nonasthmatic children. However, strong evidence suggests that smoking outside the house reduces exposure generally.

A 2003 cross-sectional survey of 164 households in the United Kingdom with at least 1 smoking parent and 1 bottle-fed infant looked for a correlation between strategies to reduce second-hand smoke and urine cotinine-to-creatinine ratios in the infants.³ Parents were classified into 3 groups according to whether they maintained a strict ban on smoking in the home, a less strict ban (smoking at home but not near the infant), or no ban.

The mean infant urinary cotinine-to-creatinine ratio was 2.43 in the no-ban group and 2.61 in the less-strict ban group (difference not significant). The combined mean for these 2 groups—2.58—was significantly higher than the mean of 1.26 in the strictest group (P<.001).

A later study recruited a convenience sample of 49 interested families with a smoking mother and a nonbreastfeeding infant between 2 and 12 months of age.⁴ Families were classified by smoking history into one of 3 groups: nonsmoking households, smoking households where efforts were made to limit smoke exposure, and smoking households where no efforts were made to limit exposure. Urine samples were obtained 3 times over 1 week. Urine cotinine levels in infants averaged 0.33 ng/mL in nonsmoking households, 2.47 ng/mL in smoking households with limited exposure, and 15.47 ng/mL in smoking households with unlimited exposure (P<.001 for all comparisons).

A case-control study that recruited families with asthmatic and nonasthmatic children assessed the effectiveness of parental behaviors to reduce second-hand smoke in 182 households with 1 smoking parent and a child between 6 and 12 years of age.⁵ Researchers measured room air nicotine and salivary cotinine concentrations.

The nicotine levels on children’s belts and in their bedrooms and the family room were approximately 3 log units lower in houses with strict smoking bans compared with households with any degree of indoor smoking (P<.0001). Similarly, salivary cotinine levels were approximately 4 log units lower in children of households with indoor smoking bans (P<.0001).

Recommendations

The United States Preventive Services Task Force (USPSTF) strongly recommends that physicians help all smoking adults to quit.⁶ The American Academy of Family Physicians endorses the USPSTF position and further advises that smoking parents be counseled about the health effects of environmental tobacco smoke on their children.⁷

The American Academy of Pediatrics⁸ and the Veterans Administration⁹ recommend urging parents to stop smoking to prevent serious health implications for their children; they further encourage pediatric clinicians to offer parents advice on quitting in order to limit children’s exposure to second-hand smoke.