Identifying patterns in psychiatric hospital stays with statistical methods: towards a typology of post-deinstitutionalization hospitalization trajectories.

Purpose: Over the past 50 years, deinstitutionalization changed the face of psychiatry. However, outpatient treatment in the community does not always fit the needs of those who left institutions and sometimes leads to frequent re-hospitalizations, a mechanism known as the "revolving door" phenomenon. The study aim was to identify different typologies of hospitalization trajectories.

Methods: Records of 892 inpatients from the Department of Psychiatry of Lausanne University Hospital were analyzed over a 3-year period with discrete sequential-state analysis.

Results: Trajectories could be split between atypical users (4.9% of patients totalling 30.6% of hospital days) and regular users. Within the atypical users group, three categories were identified: "Permanent stays" (3 patients totalling 6.3% of hospital days), "long stays" (1.7% patients/8.6% hospital days) and "revolving door" stays (2.9% patients/15.8% hospital days). The remaining 95.1% of the patients were classified into "unique episodes" (70.0% patients/24.5% hospital days) and "repeated episodes" (25.0% patients/44.9% hospital days). Diagnoses of schizophrenia were overrepresented among heavy users.

Conclusions: Most patients went through a unique or low number of brief hospital admissions over the 3 years of the study. While the shift of previously institutionalized individuals towards high users of psychiatric hospital seems limited, this phenomenon should not be neglected since 4.9% of patients use about a third of hospital beds. Early identification of problematic profiles could allow the implementation of relapse prevention strategies and facilitate the development of alternatives to hospitalization such as assertive community treatment or housing first programs.