The declining trend in Swedish youth drinking: collectivity or polarization?

AIMS: Alcohol consumption among youth in Sweden has declined markedly during the last decade. This study aims to tackle the following research questions: (i) how is the decrease in drinking distributed across consumption categories; and (ii) is the pattern of change in consumption consistent with Skog's theory of the collectivity of drinking behaviour? DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS: We analysed data from the nationally representative annual school survey of alcohol and drug habits among Swedish 9th-grade students (aged 15-16 years) covering the period 2000-12 (n ≈ 5000/year). Respondents were divided into seven drinking groups based on their relative ranking on consumption, which was measured by beverage-specific quantity and frequency items summarized into a measure of overall drinking in litres of 100% alcohol per year. In addition, the mean number of heavy episodic drinking occasions (HED) was computed for each drinking group.
FINDINGS: The decline in consumption among Swedish youth was mirrored in all seven drinking groups, although the relative decrease was smaller for heavy drinkers (top 5%) than for light drinkers (below the median). Among the top 5%, the average annual decrease was 2% (P = 0.027), while the corresponding figure for light drinkers was 28.9% (P < 0.001). The reverse pattern was true when looking at the absolute decrease. The decrease among the top 5% accounted for 26.1% of the decrease in mean consumption during the study period, whereas the light drinkers accounted for 2.9%. There was a marked relation between overall consumption, on one hand, and mean consumption and HED, on the other hand, in each of the seven drinking groups.
CONCLUSION: The marked decrease in youth drinking in Sweden that occurred during the period 2000-12 was manifest at all consumption levels. The findings are consistent with Skog's theory of the collectivity of drinking behaviour.