Mental illness and admission to general hospitals: a register investigation

Abstract

Admissions to psychiatric departments and general hospitals in an 8-year period were studied for the 17- to 49-year-old population in 2 Danish municipalities. Information was extracted from the National Patient Register and the Danish Psychiatric Register, registers containing information on all admissions to nonpsychiatric and psychiatric departments, respectively, in Denmark. Fourteen percent of the patients who had been admitted at least once to a general hospital (or 7.5% of the background population) had an indication of a mental disorder. They comprised one fourth of all general admissions of the population during the 8-year period. Patients who had been admitted to a general hospital had a 4 times greater risk of having been admitted to a psychiatric department than the rest of the population and the risk increased markedly with number of general admissions. A pronounced association was found between the number of admissions to general hospitals and psychiatric departments; i.e., both types of admissions clustered in some individuals. The excessive general admissions of psychiatric patients were found to be correlated to all types of psychiatric diagnoses, but was less prominent in nonorganic psychoses. The implication is that there is a very close association between somatic and psychiatric morbidity and that the mentally disturbed use a great part of the nonpsychiatric health services.