Determining the burden of secondhand smoke exposure on the respiratory health of Thai children

BACKGROUND The impact of secondhand smoke (SHS) on Southeast Asian children's health has been assessed by a limited number of studies. The purpose of this study was to determine whether in Thailand, pre- and postnatal exposure to SHS is associated with acute lower respiratory conditions in young children. METHODS We conducted a case control study of 462 children under age five admitted with acute lower respiratory illnesses, including asthma and pneumonia, at a major hospital in Bangkok. We selected 462 comparison controls from the well-child clinic at the hospital and matched them by sex and age. We used a structured questionnaire to collect information about exposure to SHS and other factors. We conducted bivariate and multivariate analyses to identify risk factors for acute lower respiratory conditions. RESULTS The number of cigarettes smoked at home per day by household members was significantly greater among cases. A greater number of household caregivers of cases held and carried children while smoking as compared to controls (26% versus 7%, p <0.05). Cases were more likely to have been exposed to SHS in the household (adjusted OR = 3.82, 95% CI = 2.47-5.9), and outside (adjusted OR = 2.99, 95% CI = 1.45-6.15). Parental lower educational level and low household income were also associated with respiratory illnesses in Thai children under five. CONCLUSIONS Thai children who are exposed to SHS are at nearly 4 times greater risk of developing acute lower respiratory conditions. Continued effort is needed in Thailand to eliminate children's exposure to SHS, especially at home.