AbstractBackground and Aims
The use of alterative alcohol indices in developmental research may generate conflicting findings in the literature. This study examined the longitudinal associations among four indices of alcohol involvement from ages 15 to 25 years and examined their concurrent associations with alcohol-related problems in emerging adulthood.Design
Data are from the Victoria Healthy Youth Survey, a five-wave multi-cohort study conducted biennially in Victoria, Canada between 2003 and 2011.Setting and Participants
This study included a subsample of 637 randomly recruited Canadian adolescents, aged 15–25 years.Measurements
Four indices of alcohol use were compared using multivariate piecewise growth modeling: frequency, usual quantity, heavy episodic drinking and volume.Findings
All indices increased on average from ages 15 to 21, peaked at approximately age 21, and gradually declined from ages 21 to 25. Levels of use at age 21 were highly correlated across indices (r = 0.63–0.94, P < 0.001), but correlations among rates of change varied between pairs of indices. Heavy episodic drinking and volume had the strongest correlations over time (r = 0.64–0.81, P < 0.001) and accounted for the greatest variance in alcohol use disorder symptoms (R2 = 0.35) and social and health consequences (R2 = 16) in emerging adulthood. Frequency and quantity had the weakest associations during adolescence (r = 0.49, P = 0.001) and were uncorrelated during emerging adulthood (r = 0.23, P = 0.09).Conclusions
Among Canadian youth aged 15–25 years, measures of heavy episodic drinking and volume are the most strongly correlated over time and account for greater variance in alcohol-related problems in emerging adulthood than either frequency or quantity alone.