Domestic Exposure to Tobacco Smoke in Children <10 Years: Findings From Iran’s Multiple Indicator Demographic and Health Survey (IrMIDHS-2010)

Abstract Background Secondhand smoking (SHS) is one of the important risk factors among non-communicable diseases and is responsible for more than 1% of the total burden of diseases among under five-year-old children. The prevalence of SHS among children has not been investigated both at national and provincial levels in Iran. This study was carried out to address this issue at national and provincial levels. Method: Iran’s Multiple Indicator Demographic and Health Survey (IrMIDHS) in 2010 was a multi-stage stratified cluster-random cross-sectional nationwide study over all provinces with a sample representing general population at district levels of provinces. Analyses were performed on the data of the participants who were <10 years. Data were collected by 240 trained teams over 31 provinces of Iran using standard questionnaires. Two questions about being exposed to smoking through at least one household member and number of exposure days per week were asked of the participants. Univariate and multivariable logistic regression model were utilized to assess the associated factors with SHS among children. Results: Out of a total of 111,825 participants in IrMIDHS, 18,712 of the participants were under 10 years old. About 52.48% (50.82%–52.14%) were male and 61.42% (55.42%–67.11%) resided in urban regions. Crude prevalence of SHS at this age group at national levels was 25.51% (22.48%–28.93%). After age adjustment according to the World Health Organization (WHO) population, the prevalence of secondhand smoking (SHS) at the national level was 25.59% (22.56%–28.89%). There was no significant difference between male and female participants (25.70% versus 25.48% in male and female, respectively). The highest standardized prevalence of SHS was reported from Chaharmahal and Bakhtiari, West Azerbaijan, and Hamadan provinces (44.7%, 43.9%, and 39.1%, respectively). The lowest standardized prevalence belonged to Gilan (12.8%), Golestan (14.7%), and Ilam (14.8%) provinces. Concerning the duration of exposure to SHS, 77.8% of those with history of exposure to smoke reported everyday exposure. In the multivariable model, SHS was positively associated with residence in rural areas (odds ratio = 1.31; 95% confidence interval 1.14–1.51) and age (odds ratio = 1.15; 95% confidence interval 1.03–1.28). Conclusion: SHS was relatively prevalent in 2010 among children <10 years of age in Iran. This rate was very different over the provinces. Although the prevalence of SHS among Iranian kids was found to be lower than its prevalence worldwide, through attention to easily preventable exposure to SHS along with proper legislation and cultural reforms, exposure to SHS could be markedly curbed and reduced.