Children's exposure to secondhand smoke at home before and after smoke-free legislation in Taiwan.

Introduction: In January 2009, Taiwan broadened smoke-free legislation, requiring mass transportation systems, indoor public areas and indoor workplaces with 3 or more people, to become smoke-free. We investigated the secondhand smoke (SHS) exposure at home for children aged 3-11 years in Taiwan before and after the implantation of the legislation.

Methods: We studied 7911 children from the 2005, 2009 and 2013 National Health Interview Surveys (cross-sectional, nationally representative household surveys). Logistic regression modelling estimated adjusted ORs (AOR) and 95% CIs for children's SHS exposure at home in 2009 and 2013 (2005 as reference) for the overall sample and for each category of household socioeconomic status (SES) and household composition.

Results: Prevalence of children SHS exposure at home decreased from 51% (2005) to 32% (2009) and 28% (2013). Compared to 2005, children in 2009 and 2013 had lower likelihoods of SHS exposure at home with AOR of 0.45 (95% CI 0.41 to 0.51) and 0.41 (95% CI 0.36 to 0.46), respectively. All children had reduced SHS exposure at home after the legislation, irrespective of household SES and compositions. Low household income, low parental education level, living with grandparents or living with other adults was individually associated with increased SHS exposure.

Discussion: The proportion of children exposed to SHS at home in Taiwan declined substantially from 2005 to 2009 after smoke-free legislation, and fell further by 2013, irrespective of SES and household compositions. Still, inequality in SHS exposure at home by SES and household composition warrants future research.