Can utility-weighted health-related quality-of-life estimates capture health effects of quality improvement for depression?

BACKGROUND. Utility methods that are responsive to changes in desirable out comes are needed for cost-effectiveness (CE) analyses and to help in decisi ons about resource allocation. OBJECTIVES. Evaluated is the responsiveness of different methods that assig n utility weights to subsets of SF-36 items to average improvements in heal th resulting from quality improvement (QI) interventions for depression. DESIGN. A group level, randomized, control trial in 46 primary care clinics in six managed care organizations. Clinics were randomized to one of two Q I interventions or usual care. SUBJECTS. One thousand one hundred thirty-six patients with current depress ive symptoms and either 12-month, lifetime, or no depressive disorder ident ified through screening 27,332 consecutive patients. MEASURES. Utility weighted SF-12 or SF-36 measures, probable depression, an d physical and mental health-related quality of life scores. RESULTS. Several utility-weighted measures showed increases in utility valu es for patients in one of the interventions, relative to usual care, that p aralleled the improved health effects for depression and emotional well bei ng. However, QALY gains were small. Directly elicited utility values showed a paradoxical result of lower utility during the first year of the study f or intervention patients relative to controls. CONCLUSIONS. The results raise concerns about the use of direct single-item utility measures or utility measures derived from generic health status me asures in effectiveness studies for depression. Choice of measure may lead to different conclusions about the benefit and CE of treatment. Utility mea sures that capture the mental health and non-health outcomes associated wit h treatment for depression are needed.