Convergent validity of the EQ-5D-3L in a randomized-controlled trial of the Housing First model
Health utility assessments are important for economic evaluations but few instruments have been validated in homeless people with mental illness. We examined the convergent validity of the EuroQol-5 Dimension 3-level questionnaire (EQ-5D-3L) as a measure of quality of life in homeless adults with mental illness.
Data were from Toronto participants in At Home/Chez Soi, a 24-month randomized controlled trial of Housing First (immediate access to scattered site housing and mental health support services) compared to treatment as usual for homeless adults with a mental disorder (n = 575). Participants completed the EQ-5D-3L at 6 month intervals. We tested convergent validity, hypothesizing strong correlation (r > 0.6) with the Lehman Quality of Life Interview 20 (QOLI-20) index and moderate correlations (r > 0.3) with the Colorado Symptom Index (CSI), Recovery Assessment Scale (RAS), and number of comorbidities. We also examined correlations between EQ-5D-3L scores and the QOLI-20 over time using a linear mixed-effects model.