The validity and responsiveness of the EQ-5D measure of health-related quality of life in an adolescent population with persistent major depression

Background: Despite a preference for economic evaluations to measure outcomes in terms of quality-adjusted life years, generic measures of outcome are rarely used in mental health research involving young people. Aims: To explore the validity and responsiveness of the EQ-5D measure of health-related quality of life in adolescents with major depression. Method: Data came from a clinical trial involving adolescents with persistent major depression (n = 199). Construct validity was tested using socio-demographic constructs and baseline clinical outcome scores. To assess convergent validity, correlation between EQ-5D and clinical outcome scores was tested. To assess responsiveness, the mean change in EQ-5D scores of participants categorised as improved versus not improved on clinical outcome measures was tested. Results: Significant differences in mean EQ-5D score were found for co-morbidity and three of four severity measures but not gender, age, treatment history or suicide attempts. Mean EQ-5D scores were significantly correlated with all clinical outcome measures, although relationships were moderate or weak. A change in mean EQ-5D score was significantly related to clinical assessments of improvement on all outcome measures. Conclusions: Results provide initial evidence to support the relevance of the EQ-5D in adolescents with major depression, but this evidence is weak. Replication studies are needed to assess the generalisability of these findings.