It is indicated that children are involuntarily exposed to secondhand smoke from adults, mainly at their home environment. This study aimed at describing the effectiveness of the school-based intervention to decrease the in-home smoking situation of adults so as to decrease children's exposure to secondhand smoke at home during the year 2011-2012 in a rural district in Hanoi, Viet Nam. This school-based intervention program (intervention and control group) involved 804 children aged 8 to 11 years from August 2011 to May 2012 in a rural district of Hanoi, Viet Nam. Children were taught in class about the harmful effects of secondhand smoke and about how to negotiate with fathers not to smoke in-home. Then children applied what they learnt, including staying away from secondhand smoke and persuading fathers not to smoke in-home in order to decrease children's exposure to secondhand smoke. Chi square test, t-test and multinominal logistic regression were applied in data analysis. The results showed that children's reported their father's in-home smoking decreased from 83.0% pre-intervention to 59.8% post-intervention (p < 0.001) in the intervention school while no change happened in the control school. The study found that the better changed smoking location of adult smokers as reported by children associated with the school who received intervention activities (adjusted OR = 2.04; 95% CI: 1.28-3.24). Poorer changed attitudes towards secondhand smoke of children associated with a lower percentage of better change in smoking location of their fathers/other adult smokers (aOR = 0.51, 95% CI: 0.28-0.96). Children's poorer changed knowledge towards secondhand smoke also associated with poorer changed smoking location of adult smokers (aOR = 2.88, 95% CI: 1.07-7.76). It is recommended by this study that similar school based intervention approaches should be applied in primary schools in Viet Nam to increase children's awareness on the adverse health effects of secondhand smoke and to help them to be able to avoid their exposure to secondhand smoke at their home environment.
Keywords: Viet Nam; adults; children; exposure; in-home smoking; school-based intervention; secondhand smoke.