Trend over time on knowledge of the health effects of cigarette smoking and smokeless tobacco use in Bangladesh: Findings from the International Tobacco Control Policy Evaluation Bangladesh Surveys

INTRODUCTION: Cigarette smoking and smokeless tobacco (ST) use are prevalent in Bangladesh. This longitudinal study examined how knowledge of the health effects of smoking and ST use in Bangladesh has changed overtime with the country's acceleration of tobacco control efforts. METHODS: Data were analysed from the International Tobacco Control Survey, a nationally representative longitudinal study of users and non-users of tobacco (aged 15 and older) in Bangladesh, across four waves conducted in 2009 (n = 4378), 2010 (n = 4359), 2012 (n = 4223) and 2015 (n = 4242). Generalised estimating equations assessed the level of knowledge about harms of tobacco use across four waves. Multivariable logistic regressions assessed whether knowledge of health effects from cigarette smoking and ST use in 2015 differed by user group. RESULTS: In 2015 survey, most tobacco users were aware that cigarette smoking causes stroke (92%), lung cancer (97%), pulmonary tuberculosis (97%) and ST use causes mouth cancer (97%) and difficulty in opening mouth (80%). There were significant increases in the total knowledge score of smoking related health harm from 2010 to 2012 (mean difference = 0.640; 95% confidence interval [CI] 0.537, 0.742) and 2012 to 2015 (mean difference = 0.555; 95% CI 0.465, 0.645). Participants had greater odds of awareness for ST health effects from 2010 to 2015. DISCUSSION AND CONCLUSIONS: The results suggest that increasing efforts of awareness policy interventions is having a positive effect on tobacco-related knowledge in Bangladesh. These policy initiatives should be continued to identify optimal methods to facilitate behaviour change and improve cessation of smoking and ST use.