Although scientifically controversial, continuity of care for patients with serious mental illness has long been a key-concept in the evaluation of deinstitutionalized mental health services. It is associated with systems integration, and particularly relevant in transitions from in- to outpatient status at the individual level. The theme is highlighted in a close to natural experiment that was part of the VELO-project, were two neighboring mental health service-systems diverge concerning their organization of in- and outpatient services.

To investigate the significance of systems integration of inpatient and outpatient services on continuity of care for individual patients.

244 inpatients from the services case-registry (2005) were followed concerning their pattern of both inpatient and outpatient service use. The results were controlled for length of hospitalization, diagnosis and demographical variables.

Overall for inpatients, the low-integrated system shows significantly less outpatient activity than the high-integrated system. This pattern is not associated with differences in general service profile of the systems, and holds up for patients suffering from schizophrenia and anxiety, but not for affective disorders.

The results may be explained by differences in geographical and managerial organization of the two systems.

High level of systems integration is important in reducing the risk of discontinuity of care for patients suffering from severe mental health problems. Level of integration may interact with differences in vulnerability for transitions of individual patients.