Treatment for alcohol dependence in Catalonia: health outcomes and stability of drinking patterns over 20 years in 850 patients.

AIMS: The aim of this study was to evaluate long-term outcomes in alcohol-dependent patients following outpatient treatment and gender differences in drinking outcome and mortality.
METHODS: A 20-year longitudinal prospective study was done with interim analyses at 1, 5 and 10 years. Of the original sample of 850 patients, 767 (90%) were located 20 years later and 393 of these were interviewed. 273 (32%) patients died during the intervening period and 101 (12%) no longer wished to participate in the study. Drinking status was assigned based on the 12 months prior to the follow-up interview.
RESULTS: At the 20-year follow-up, 277 (32.6%) of the 393 patients for whom drinking status could be assigned were abstinent (defined never drinking or drinking on less than occasion per month and never more than four drinks/drinking occasion.), 29 (3.4%) were controlled drinkers and 87 (10.2%) were heavy drinkers. Controlled drinking was the least stable category, with 23% continuing from year 5 to year 10 in that category, and 10% continuing in that category from year 10 to year 20. Mortality was higher (39.1%) in those who had been categorized at year 5 as heavy drinkers compared to those who had been categorized as controlled drinkers or abstinent. Abstinent patients reported fewer alcohol-related problems and better psychosocial functioning than heavy drinkers. Women achieved higher abstinence rates (47.2% versus 29.0%, P = 0.005) and had lower mortality (22.4% versus 34.5%, P = 0.03) than men.
CONCLUSIONS: Over the long-term, abstinence is the most frequent and stable drinking outcome achieved and is associated with fewer problems and better psychosocial functioning. Controlled drinking is rarely achieved and sustained. Women appear to do better than men in the long term.