To our knowledge, this is the first study to examine smoke-free–home rules in a population-based sample of women with infants in the United States. A high percentage of women reported having complete smoke-free–home rules. This estimate is higher than the estimate found in the 2006–2007 Tobacco Use Supplement to the Current Population Survey; in this survey of US households with children aged 17 years or younger, 83.9% of households had complete smoke-free–home rules (11
). We observed a significant increase in the prevalence of smoke-free–home rules in 3 of the 5 states in our analysis, although the prevalence was high for all study states. This increase may reflect differences in the presence of state or local laws banning smoking in public spaces. Several studies have found increases in the adoption of smoke-free–home rules after comprehensive smoke-free laws were implemented (12
). During the study period, New Jersey in 2006 and Washington in 2005 implemented comprehensive state laws eliminating smoking in public places and workplaces, including restaurants and bars; Maine had a law in place making restaurants and bars smoke-free at the start of the study period (2004) but did not eliminate smoking in private workplaces until 2009; Oregon did not completely eliminate smoking in private workplaces, restaurants, and bars until 2009; and Arkansas implemented partial smoking restrictions in 2006, which made private workplaces smoke-free but exempted restaurants and bars (6
). Our findings show that efforts by public health practitioners and clinicians to increase awareness of the health effects of secondhand smoke on infants might have been successful. Because public smoking restrictions have been associated with increases in smoke-free–home rules and decreases in smoking prevalence (12
), we suspect that the prevalence of complete smoke-free–home rules remains high or may have increased in these states since 2008; however, follow-up is needed to assess these trends.
Although the prevalence of partial and no rules was low, an estimated 75,000 women with infants in these study states are living in homes that do not have a complete smoke-free–home rule, and of these women, half are current smokers, likely exposing their infant to second- and thirdhand smoke (ie, tobacco smoke that remains in clothes, hair, and surroundings after a cigarette is extinguished) (17
). The characteristics of women with infants who had a partial or no rule (current smokers, non-Hispanic black women, and women who have <12 years of education) in our study were consistent with characteristics of women in other studies that have examined smoke-free–home rules among households with children of any age (18
). Additionally, 44% of women who had partial or no rules were nonsmokers in our study. These women may share their households with partners, other relatives, or guests who smoke in the home (21
). In our study, almost all women who had partial or no rules attended infant well-baby visits, and more than two-thirds of these women attended a postpartum checkup or participated in WIC. A woman’s visit to her prenatal care provider may end within 6 weeks after delivery, so well-baby visits or participation in other programs, such as WIC, offer repeated opportunities for providers to ask women and their partners about tobacco use and exposure to second- and thirdhand smoke; providers should advise all families to make their homes, cars, and other environments completely smoke-free (22
). Furthermore, systems-based changes — entering data on secondhand smoke exposure into electronic medical records or reimbursing for counseling on tobacco exposure, for example — could help reduce barriers to intervention among providers (23
This study has several limitations. First, the presence of a smoke-free–home rule was self-reported by the mother, so prevalence could have been overestimated. Also, we have no information on whether these rules are enforced. However, other studies have found that parental report of home rules correlates with biomarkers for exposure to secondhand smoke among children (24
). Second, we were not able to assess the presence of other smokers living in the household, which is an important predictor of secondhand smoke exposure in the home. Third, our findings are generalizable only to women with infants in the study states, and therefore may not be generalizable to the entire United States. Although the response rates ranged from 71% to 82%, the PRAMS methodology weights data to account for nonresponse. A potential selection bias may result if the weighting procedure does not fully address nonresponse. Fourth, the regression analysis combined data sets across multiple years to increase sample size. There exists the small possibility that mothers who had multiple pregnancies in these states from 2004 through 2008 were represented more than once. Because data from different years are not linked by mother, we were unable to account for correlation by mother in our analysis, but the likelihood of the women being sampled twice is low. We also included state and year in the model to reduce potential confounders of using a combined data set. Finally, PRAMS does not ask about smoke-free rules in other settings where infants may be exposed to secondhand smoke, such as vehicles, day care, or school. However, infants spend most of their time at home, and home is the primary source of secondhand exposure for this age group (2
A high percentage of women with infants in this study reported a complete smoke-free–home rule, suggesting successful public health and clinical efforts to educate parents about the risk of secondhand smoke exposure to infants. Efforts are still needed to reach small groups of women, including current smokers, who are least likely to have complete smoke-free–home rules. Additionally, counseling women about the health risks of secondhand smoke among children and continuing to promote the adoption of smoke-free–home rules at well-baby visits and obstetric/gynecologic visits and in other programs, such as WIC, may help to further reduce secondhand smoke exposure among infants and to improve short- and long-term infant health outcomes.