How mental health service systems are organized may affect the rate of acute admissions to specialized care: Report from a natural experiment involving 5338 admissions

OBJECTIVES Studies on the dynamics between service organization and acute admissions to psychiatric specialized care have given ambiguous results. We studied the effect of several variables, including service organization, coercion, and patient characteristics on the rate of acute admissions to psychiatric specialist services. In a natural experiment-like study in Norway, we compared a "deinstitutionalized" and a "locally institutionalized" model of mental health services. One had only community outpatient care and used beds at a large Central Mental Hospital; the other also had small bed-units at the local District Psychiatric Centre. METHODS From the case registries, we identified a total of 5338 admissions, which represented all the admissions to the psychiatric specialist services from 2003 to 2006. The data were analyzed with chi-square tests and Z-tests. In order to control for possible confounders and interaction effects, a multivariate analysis was also performed, with a logistic regression model. RESULTS The use of coercion emerged as the strongest predictor of acute admissions to specialist care (odds ratio = 7.377, 95% confidence interval = 4.131-13.174) followed by service organization (odds ratio = 3.247, 95% confidence interval = 2.582-4.083). Diagnoses of patients predicted acute admissions to a lesser extent. We found that having psychiatric beds available at small local institutions rather than beds at a Central Mental Hospital appeared to decrease the rate of acute admissions. CONCLUSION While it is likely that the seriousness of the patients' condition is the most important factor in doctors' decisions to refer psychiatric patients acutely, other variables are likely to be important. This study suggests that the organization of mental health services is of importance to the rate of acute admissions to specialized psychiatric care. Systems with beds at local District Psychiatric Centers may reduce the rate of acute admissions to specialized care, compared to systems with local community outpatient services and beds at Central Mental Hospitals.