The virtual institution: cross-sectional length of stay in general adult and forensic psychiatry beds

Background: Length of stay in psychiatric hospitals interests health service planners, economists and clinicians. At a systems level it is preferable to study general adult and forensic psychiatric beds together since these are likely to be inter-dependent. We examined whether patients were placed according to specialist need or according to their cross-sectional length of stay. Methods: A one night census of all registered mental nursing home (RMNH) beds was carried out for a defined catchment area of 1.2 m population in north London in November 1999. This included all public sector psychiatric hospital beds, independent sector and forensic beds in and outside the catchment area. Cross-sectional length of stay was defined as time since the date of admission from the community. Log rank (Mantel-Cox) Chi squared was used to test for differences between groups and hierarchical logistic regression for statistical modelling. Results: There were 1,085 occupied psychiatric beds. Cross-sectional LOS was greater than 365 days in 43.5%. Forensic beds had longer cross-sectional LOS than general beds. LOS increased with the level of therapeutic security from open through low, medium and high secure. Cross-sectional LOS was shorter for open hospital beds than community RMNH beds, shorter for informal patients than those detained under civil mental health law, and longest for forensic detentions. Longest cross-sectional LOS were for patients placed in RMNHs in the community, 10.7% of whom were 'forensic' as were 25.4% of low secure patients. Designated length of stay (acute, rehab/medium term and long term) was also associated with increasing cross-sectional LOS. In regression analysis only three variables contributed to a model of cross-sectional LOS, commissioning status (general or forensic), designated length of stay and designated level of therapeutic security. Conclusions: Studying cross-sectional LOS for whole systems (all psychiatric beds) is essential for operational health service management. At the time of this survey 'forensic' status was the main way of accessing long term high dependency places. This has been an organic development over time, a response to patient needs rather than the outcome of any specific policy or plan.