Reducing secondhand smoke exposure at home in rural areas, Thailand: a cluster randomised controlled trial.

Secondhand smoke (SHS) exposure cause of morbidity and mortality, especially in non-smokers and children. This study tested the effectiveness of an intervention for reducing exposure to SHS in homes by creating smoke-free environment where 1 to 5-year old infants reside. A cluster randomised controlled trial was conducted in a rural geographic area of Thailand, with 47 villages assigned to either an intervention or a comparison group. The intervention consisted of self-education and infographic material, together with 45 text messages delivered via short message service. The control group received the self-education after the intervention at 3 months. The primary outcome was assessed by parent´s self-reported in exposure to SHS in home. Multiple logistic regression was used to test the effect of the intervention. The effects of the intervention increased the likelihood of a reducing exposure to SHS at home by 1.8-fold (95%CI 1.04 to 3.11). The average number of days of SHS exposure at home (7 days) also decreased by -1.25-fold (95%CI -1.85 to -0.66) in the intervention group. The effectiveness of the intervention in reducing SHS exposure at home by a creating a smoke-free environment was observed to be statistically significant.