Changes in sobriety in the Swedish population over three decades: age, period or cohort effects?

AIMS: This study aimed to examine age, cohort and period trends in alcohol abstinence. DESIGN: Two surveys, the Level of Living Survey collected in 1968, 1974, 1981, 1990 and 2000, and the Swedish Panel Study of the Oldest Old (SWEOLD) collected in 1992 and 2002, were studied with graphical depictions of cross-sectional and longitudinal data presented over time and over age. Cross-sectional 10-year age group differences, time-lag differences between waves and within-cohort differences between waves for 10-year birth cohorts were examined. Logistic regression models were applied to confirm the observed patterns. SETTING: The samples were representative of the Swedish population. PARTICIPANTS: Participants ranged in age from 18 to 75 (n = 5000 per wave), and 77+ at later waves (n = 500). MEASUREMENTS: Alcohol abstinence was determined by asking ‘Do you ever drink wine, beer, or spirits?’, where a ‘no’ response indicated abstinence. FINDINGS: Decreases in abstinence rates were observed from 1968 to 2000/02. While cross-sectional analysis indicated increased abstinence with advancing age, the longitudinal analysis suggested otherwise. Inspection of cohort differences revealed little change within cohorts and large differences between cohorts; abstinence rates declined in later-born cohorts up to the 1940s birth cohorts; stability was observed in cohorts born since the 1940s. Logistic regression models indicated that neither age nor period were significant (P > 0.05) predictors of abstinence when cohort (P < 0.001) was included. CONCLUSION: Decreasing proportions of total alcohol abstainers in Sweden from 1968 to 2000 appear to be attributable primarily to decreases in successive cohorts rather than drinkers becoming abstainers.