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 nonalcohol 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.