Does Drinking Initiation of Young Thai Drinkers Vary Over Time and Generation? Results of the National Surveys on Tobacco and Alcohol Consumption of the Thai Populations 2007 to 2017

BACKGROUND Early age at drinking initiation may be one factor responsible for underage drinking in Thailand and this may be affected by cultural and generational changes over certain periods of time. This study aimed to explore the effects of time period and generation on drinking onset of young Thai drinkers in the past decade. METHODS We analyzed data from a total of 60,018 Thais aged 15 to 24 years from 4 national surveys conducted in 2007, 2011, 2014, and 2017. We used multilevel and event history analysis to examine the effects of period (survey year) and cohort (birth year of participants), adjusted for sex, age, area of residence, and region on drinking onset. RESULTS The overall prevalence of past-year drinking was 23.6 % (95% confidence interval [CI]: 23.2, 23.9) among participants of all surveys. Cox proportional hazards model revealed significantly different probabilities to have initiated drinking between participants of different surveys and birth years, indicating significant period and cohort effects. After adjusting for sex, age, cohort, living region, and area of residence, participants in the 2014 survey had the highest likelihood to have started drinking (hazard ratio [HR]: 1.25 CI: 1.15 to 1.36), compared to the participants of the same age in the 2007 survey while those in the 2011 (HR: 0.89, CI: 0.85, 0.93) and 2017 (HR: 0.63, CI: 0.58, 0.68) surveys had less likelihood. Participants born in 1993 to 2002 (later cohort) had higher probability to have started drinking than those born in 1983 to 1992 (HR: 1.80, CI: 1.69, 1.92). CONCLUSION Thai youths of the recent generations living in recent years tend to have a higher probability of initiating drinking than those in the past. Interventions to prevent underage drinking should begin earlier for the young generation.