Measuring health-related quality of life in bipolar disorder: Relationship of the EuroQol (EQ-5D) to condition-specific measures

Generic utility measures of health-related quality of life provide an independent net valuation of health states. They are increasingly used with condition-specific outcome measures in assessing treatments. In Bipolar Disorder, a few studies indicate poorer quality of life for depressed vs. euthymic patients. A single study suggests mania is less negative than depression. This analysis examines the relationship of one such scale, the EuroQol (EQ-5D), to objective and subjective measures of depression and mania in 221 Bipolar subjects, recently or still in an episode of illness. Results: Depressed patients showed a very poor quality of life (median EQ-5D Index score 0.41). Index and Visual Analogue scores improved significantly as level of depression decreased (Jonckheere–Terpstra test p<0.001). Both scores were significantly negatively related to all depression measures. Patients reported problems across all areas of life covered by the EQ-5D. No such relationships were observed between EQ-5D scores and mania measures, though all mania measures were inter-related. However, the range of mania shown was quite restricted. Conclusions: The EQ-5D is a useful measure of quality of life for Bipolar patients suffering from depression. Conclusions about the role of the EQ-5D in mania are restricted by the limited range of mania observed.