PREDICTORS OF OUTPATIENT MENTAL-HEALTH UTILIZATION BY PRIMARY-CARE PATIENTS IN A HEALTH MAINTENANCE ORGANIZATION

Objective: The authors examined the volume and predictors of outpatien t mental health utilization among primary care patients in a large sta ff-model health maintenance organization (HMO). Method: Consecutive pr imary care patients (N=1,810) were screened by using the 12-item Gener al Health Questionnaire, and a stratified random sample (N=373) comple ted the 28-item General Health Questionnaire and Composite Internation al Diagnostic Interview. Telephone interviews and computerized records were used to examine use of mental health services inside and outside the HMO over the following 3 months. Results: Over 3 months, 6.7% of the screened patients used mental health services within the HMO. Util ization increased with higher General Health Questionnaire score (2.9% among those scoring 0, 22.3% among those scoring 8 or more) and decre ased with higher out-of-pocket cost for mental health visits (7.5% for those with no charge, 3.3% for those paying $30/visit). Among the int erviewed subjects, 5.1% used mental health services within the HMO (me an=2.92 visits) and 8.9% used outside mental health services (mean=8.8 6 visits). Use of outside services was more strongly related to sociod emographic factors, and use of inside services was more related to sev erity of psychological disorder. Conclusions: Among these subjects, us e of mental health care was high and services purchased outside the HM O exceeded those inside the HMO. Increasing copayment levels progressi vely reduced demand without respect to severity of illness. Attempts t o control outpatient mental health costs must address equity and clini cal need.