Do smoke-free laws or policies impact smoking at home? A comparison between smoke-free and nonsmoke-free jurisdiction in India

Abstract

Background: Globally, various studies have looked at the effect of smoke-free declaration in public spaces on secondhand smoke (SHS) exposure at home. However, a formal evaluation has not been reported from India. We assessed and compared smoking at home in two jurisdictions in India – a compliance-validated smoke-free jurisdiction (Shimla in 2010) versus a nonsmoke-free jurisdiction (Haridwar) between 2009 and 2015. Methods: We randomly sampled 247 households (with one smoker at least as on October 2009) each in Shimla (n = 123) and Haridwar (n = 124) during July–August 2015. Through an interviewer-administered questionnaire, information on number of bidi/cigarette smoked per day in the household (at home and at work) was collected from the smoking member across five time points: 2009, 2010, 2011, 2012, and 2015. From the nonsmoking member, we collected information regarding change in number of smokes per day and change in place of smoking in the household before and after 2010. We fitted a mixed effects maximum likelihood regression using random intercepts model for the effect of smoke-free declaration on number of smokes per day by the household adjusted for baseline differences, secular trends, clustering of data, and other potential confounders (time/year, number of children, number of adults, annual household income, and type of tobacco). Results: Introduction of smoke-free declaration in Shimla resulted in a decrease (over 1 year) of 1.24 (0.95 confidence interval [CI]: 0.8, 1.7), 0.55 (0.95 CI: 0.14, 0.96), and 0.98 (0.95 CI: 0.3, 1.6) bidi/cigarette smoked per day per household at home, at work, and at “work and home combined,” respectively. Within homes, when compared to Haridwar, there was an improved desirable behavior such as reduction in smoking within home and increase in smoking outside home in Shimla (reported by nonsmoking member). Conclusion: Smoke-free laws in public spaces in Shimla, India, were associated with the reduction in SHS exposure at home.