Observed Outcomes: An Approach to Calculate the Optimum Number of Psychiatric Beds.

The number of psychiatric beds, in most developed countries, has decreased progressively since the late 1950s. Many clinicians believe that this reduction has gone too far. But how can we determine the number of psychiatric beds a mental health system needs? While the population health approach has advantages over the normative approach, it makes assumptions about optimal and minimum duration of hospitalization required for various psychiatric disorders. In this paper, we describe a naturalistic approach that estimates the required number of psychiatric beds by comparing the bed levels at which negative outcomes develop in different jurisdictions. We hypothesize that there will be a threshold below which negative outcomes will be seen across jurisdictions. We predict that hospital key performance indices will be more sensitive to bed reductions than the clinical and social outcomes of patients. The observed outcome approach can complement other approaches to determining bed numbers at the national and local levels, and should be a priority for future health services research.