Using health status measures with the seriously mentally ill in health services research.

Changes in the delivery of mental health care have prompted interest in using generic health status measures to test the effect of system change on those receiving treatment. Of special concern are those with serious and persistent mental illness who may be neglected when cost containment efforts reduce the availability of treatment services. This population may be affected by these changes, which might go undetected if investigators use scales that measure only pathology and not the full spectrum of well-being. The purpose of this study was to test the feasibility of using self-report health status measures with this population, to describe the psychometric properties of the scales, and to report the health status scores of a random sample of the Medicaid psychiatrically disabled population. We found that the four health status scales had adequate psychometric properties, that score variability was high, the distributions normal, and that patterns of association with more traditional clinical measures were of the expected size and direction. One scale, General Health Perceptions, had reliability and item-to-score correlation below acceptable levels.