Effect of coverage on use of an HMO alcoholism treatment program, outcome, and medical care utilization.

Two-hundred-fifty alcoholics were randomly assigned to a full benefit of 50 per cent copayment group before entering an HMO (health maintenance organization) alcoholism treatment program. Data on use of treatment services, use of medical care services, and drinking behavior were collected for one year after intake. The medical care utilization and drinking behavior data were compared to data for the year before intake. The two coverage groups were comparable on sociodemographic characteristics and baseline drinking behavior, but the full benefit group tended to have higher utilization rates for the year prior to intake and significantly more treatment contracts than those having the 50 per cent copayment requirement. Changes in use of medical care services were similar in both groups. Both payment groups improved, but the full benefit group tended to be somewhat more improved. Regression analysis supported the relative unimportance of extent of alcoholism coverage in affecting outcome and subsequent medical care utilization.