Prices, alcohol use initiation and heavy episodic drinking among Chilean youth

AIMS: To examine the association between alcohol prices and age of initiation of alcohol use and the association between age of alcohol use initiation and heavy episodic drinking (HED) among adolescents in Chile. DESIGN: We estimated discrete-time hazard models using retrospective data and generalized ordered probit models with repeated cross-sectional data. SETTING: Chile. PARTICIPANTS: A total of 248 336 urban youth who attended secondary school between 2003 and 2015 and self-reported ever having tried alcohol. MEASUREMENTS: We created drinking histories from self-reported responses of age, age of alcohol use initiation and year/month of survey. From two self-reported responses, we created a four-category ordinal variable of heavy episodic drinking: none, one to two, three to nine and more than 10 HED episodes in the past 30 days. We constructed a monthly measure of real alcohol prices using the all-items and alcohol component of the Consumer Price Index compiled by Chile's statistical agency, the Instituto Nacional de Estadísticas. FINDINGS: First, we found negative, statistically significant and policy-meaningful associations between alcohol prices and the age of alcohol use initiation. The estimated price elasticity of delay was -0.99 [95% confidence interval (CI) = -1.30, -0.69]. A 10% increase in real alcohol prices was associated with delayed alcohol use initiation of approximately 6.6 months. Secondly, we found that youth who had started drinking alcohol at a later age had statistically significant and substantially lower probabilities of having reported HED during the previous month. For example, youth who started drinking at 16 were 4.9 (95% CI = 4.2-5.6) percentage points more likely to have reported no HED in the previous month relative to youth who started drinking alcohol when aged 12 years or younger. CONCLUSIONS: Increasing the price of alcohol products may delay alcohol initiation among young people in Chile. Chilean youth who start drinking alcohol later may engage in less harmful drinking practices.