Association between tobacco control policies and hospital admissions for acute myocardial infarction in Thailand, 2006-2017: A time series analysis

INTRODUCTION: Studies in many countries have documented reductions of acute myocardial infarction (AMI) hospitalizations with smokefree policies. However, evidence on the association of cigarette tax with AMI events is unclear. There have been no studies of the associations between these two policies and AMI hospitalizations in Thailand. METHODS: We used negative binomial time series analyses of AMI hospitalizations (ICD-10 codes I21.0-I21.9), stratified by sex and age groups, from October 2006 to September 2017 to determine whether there was a change in AMI hospitalizations as a result of the changes in cigarette prices and the implementation of a 100% smokefree law. RESULTS: Cigarette price increases were associated with a significant 4.7% drop in AMI hospitalizations among adults younger than 45 (incidence rate ratio [IRR], 0.953; 95% confidence interval [CI], 0.914-0.993; p = 0.021). Implementation of the 100% smokefree law was followed by a significant 13.1% drop in AMI hospitalizations among adults younger than 45 (IRR, 0.869; 95% CI, 0.801-0.993; P = 0.001). There were not significant associations in older age groups. CONCLUSIONS: The Thai cigarette tax policy and the smokefree law were associated with reduced AMI hospitalizations among younger adults. To improve effectiveness of the policies, taxes should be high enough to increase cigarette price above inflation rates, making cigarettes less likely to be purchased; smokefree laws should be strictly enforced.