Am J Psychiatry 137:2, February 1980 207 Diagnosis of Mental Disorder in Adults and Increased Use of Health Services in Four Outpatient Settings BY EDWIN W. HOEPER, M.D.. GREGORY R. NYCZ, DARREL A. REGIER, M.D., M.P.H., IRVING D. GOLDBERG, M.P.H., ALAN JACOBSON, M.D., AND JANET HANKIN, PH.D. The differential use ofmedical services by patients with and those without a diagnosis ofmental disorder was examined infour adult populations by age, sex, diagnosis, and medical department used. The four settings offered comprehensive services to patients t’ho varied greatly in socioeconomic status. In allfour settings patients it’ith a diagnosis ofmental disorder used all services and general health services more than patients without such a diagnosis. Results document increased medical morbidity and a greater likelihood ofa diagnosis ofan ill-defined condition in patients with mental disorder than thatfound in patients without a diagnosis ofmental disorder. A number of studies (1-3) have demonstrated in- creased use of general health care services by pa- tients with a diagnosis of mental disorder. Regier and associates studied four integrated general health and mental health care systems and found that patients with a diagnosis of mental disorder had a higher mean number of visits to providers of general health care than patients without a diagnosis of mental disorder. (This study was presented at a conference on HMOs sponsored by the Alcohol, Drug Abuse, and Mental Health Administration on November 30, 1977.) Two hypotheses have been proposed for the in- creased use of health cane services by people with a diagnosis of mental disorder. One proposes that for a ‘ given level of medical morbidity people with psycho- Presented at the 13 1st annual meeting of the American Psychiatric Association, Atlanta, Ga., May 8-12, 1978. Received May 22, 1978; revised Jan. 19, 1979; accepted Feb. 23, 1979. From the Marshfield Clinic and St. Joseph’s Hospital, Marshfield, Wis. (Dr. Hoeper); the Marshfield Medical Foundation, Marshfield, Wis. (Mr. Nycz); the Division of Biometry and Epidemiology (Dr. Regier) and the Applied Biometrics Research Branch (Mr. Gold- berg), National Institute of Mental Health, Rockville, Md. ; the los- lin Clinic and the Department of Psychiatry, Harvard University Medical School, Boston, Mass. (Dr. Jacobson); and the Health Services Research and Development Center, Johns Hopkins Uni- versity, Baltimore, Md. (Dr. Hankin). Address reprint requests to Dr. Hoeper, Marshfield Clinic, 1000 North Oak Ave. , Marshfield, Wis. 54449. This work was supported by contracts 278-76-0027(DB), 278-76- 0028(DB), and 278-76-0058(DB) from the National Institute of Men- tal Health. logical symptoms may have a greater propensity to seek health care (4-6). The second suggests that people with mental disorders have increased medical morbidity (7, 8) and mortality (9-1 1). Methodological problems (8) have prevented clarification of the rca- sons for the observed increased use of health care services by people with a diagnosis of mental disorder. In this paper we will examine the difference in use of medical services between patients with and those without a diagnosis of mental disorder in an adult pop- ulation (18-64 years old) by age, sex, diagnosis, and medical department used. We will particularly empha- size determining the extent to which differential use of medical services appears to reflect increased morbidi- ty and/on an increased propensity to seek cane. METHOD All data on use of services were obtained from a study sponsored by the National Institute of Mental Health. The study collected population, use, and cost information for calendar year 1975 in four organized health care settings: 1) the Columbia Medical Plan, a prepaid group practice serving a predominantly upper- middle-class suburban population of 18,875 in Colum- bia, Md., 2) the Greater Marshfield Community Health Plan, a prepaid health plan using the Marshfield Clinic (a multispecialty group practice) to serve 19,785 rural residents in Marshfield, Wis. , 3) the fee-for-service plan ofthe Marshfield Clinic, serving 29,780 rural resi- dents ofthe greater Marshfield area, who receive their care on a fee-for-service basis in Manshfield, and 4) the Bunker Hill Health Center, a government-subsidized fee-for-service multispecialty group practice commu- nity health center serving a predominantly working- class, indigent, urban population of 1 1 ,794 people in the Charlestown section of Boston, Mass. All of these settings provide comprehensive services; the geneEal health and mental health services are physically, ad- ministnatively, and professionally integrated. Abstracting data on use of services by the adult pop- ulation in these four settings, we computed the overall average visit rates and the ratios of mean visit rates for patients with and those without a diagnosis of mental disorder by age and sex. Similar data were obtained after eliminating all visits to mental health providers.