Putting the 'Q' in depression QALYs: a comparison of utility measurement using EQ-5D and SF-6D health related quality of life measures

Generic health preference measures that capture quality of life improvements in depression are important for economic analysis of new technologies. To compare two widely used preference measures, the EQ-5D and SF-6D, in terms of their dimensions and health utility values. EQ-5D and SF-6D data collected from 114 patients with depression, who participated in a cluster, randomised controlled trial to evaluate a collaborative care intervention in UK, primary care practices. Utilities were examined across the whole sample and by level of depression severity using the PHQ-9. Depression was associated with disutility at baseline. At 3 month follow-up mean utility increased 0.147 for EQ-5D and 0.082 for SF-6D. Health gains were observed in patients in remission from depression and those with the mildest level of depression severity. Both generic preference measures were sensitive to health gains in depression within a relatively short follow-up period; larger health gain was observed for the EQ-5D.