Heterogeneous dose-response and college student drinking: examining problem risks related to low drinking levels.

BACKGROUND AND AIMS: Previous research demonstrates that the number of problems related to each additional drink consumed on any drinking occasion, dose-response, varies non-linearly across average drinking quantities. We test predictions from a dynamic model of drinking behavior that locates this heterogeneity in drinkers' efforts to equilibrate between costs and benefits of use. DESIGN: Equations derived from the theoretical model are used to assess dose-response across drinking quantity subgroups using censored regressions. SETTING: Fourteen California, USA, college campuses surveyed from 2003 to 2011. PARTICIPANTS: A total of 37 762 undergraduate college students 18 years of age and older. MEASUREMENTS: Drinking patterns, five physiological problems related to alcohol use (hangover, memory loss, medical treatment for overdose, nausea/vomiting, passing out) and student demographics. FINDINGS: The number of physiological problems related to each additional drink consumed was an inverse function of average drinking quantities (b = 0.2947, Z = 21.92, P<0.001), differed by drinker age (of-age drinker b = -0.1144, Z = -3.95, P < 0.001) and gender (male b = -0.3379, Z = -18.56, P<0.001) and, at the population level, drinking three drinks per occasion was associated with the greatest number of problems. CONCLUSIONS: Among US college students, all drinkers exhibit greater risks for physiological problems related to alcohol use (hangover, memory loss, medical treatment for overdose, nausea/vomiting, passing out) when drinking greater amounts of alcohol, but heavier drinkers (those who consume more on average) exhibit fewer problems for each additional drink consumed (less dose-response) than light and moderate drinkers. Light and moderate drinkers exhibit greater dose-response, with three drinks per occasion associated with the greatest number of problems.