Alcohol use and medical care utilization among health maintenance organization patients in the emergency department.

OBJECTIVE To determine the association of an alcohol-related ED visit with medical care utilization during a two-year period surrounding the ED visit in an HMO. METHODS A probability sample of ED patients were interviewed and underwent breath analysis in a large HMO in a Northern California county. Based on recent alcohol intake or documentation of an alcohol-related ED visit, the patients were assigned to an alcohol group (n = 91) or a non-alcohol group (n = 897). A 10% random sample of the health plan membership of the same county (n = 19,968) served as a comparison group. Utilization data were obtained from computerized files. Multiple linear regression was used to determine differences in subsequent outpatient visit rates between the alcohol and the non-alcohol groups. Logistic regression was used to compare the risks of hospitalization in the two groups. RESULTS Annual outpatient visit rates were 7.8 in the alcohol group and 8.3 in the non-alcohol group (p = 0.65), controlling for gender, age, and injury status, and were significantly different from the visit rate of 5.5 for the random health plan sample (p = 0.0001). No difference was found between the alcohol and the non-alcohol groups for risk of hospitalization; however, those in the health plan sample were less than half as likely to be hospitalized as were those in the non-alcohol group (odds ratio 0.44, p = 0.002). CONCLUSIONS No difference was found in utilization of medical services between the alcohol and the non-alcohol groups in this predominantly white, well-educated HMO ED population. However, both groups used significantly more inpatient and outpatient services than did the general HMO membership.