Responsiveness of the EQ-5D to HADS-identified anxiety and depression

RATIONALE: The use of generic measures of health-related quality of life enables cost effectiveness comparisons of different health care interventions to be made. Nevertheless, there exists a concern that generic instruments may be insufficiently sensitive to detect the differences or changes in outcome identified by condition-specific instruments. This paper compares the psychometric properties of the EQ-5D generic instrument with a widely used specific measure of distress, the Hospital Anxiety and Depression Scale (HADS). METHOD: The analysis was based on data obtained from a large sample of women (n = 3119) with low-grade cervical cytological abnormalities detected at routine screening. These women completed EQ-5D and HADS questionnaires at recruitment and at 12 months thereafter. We examined the strength of association between HADS-determined severity of distress and EQ-5D scores at recruitment and between changes in severity and in scores over time. RESULTS: A higher likelihood of HADS-identified anxiety and/or depression was associated with significantly lower EQ-5D index and visual analogue scores. Over time, the EQ-5D score rose significantly when the likelihood of an individual representing a HADS-defined anxiety and/or depression case decreased. CONCLUSION: We conclude that the EQ-5D has shown itself to be responsive to differing degrees of HADS-assessed distress, although generalization beyond the UK context requires further investigation.