Operationalising the capability approach for outcome measurement in mental health research

The OxCAP-MH item response rate was 90%-68%. There were significant correlations between service users' overall capability scores and the GAF, EQ-5D VAS and EQ-5D-3L utilities (corr = 0.249, 0.514, 0.415, respectively). The most affected capability domains were: 'Daily activities', 'Influencing local decisions', 'Enjoying recreation', 'Planning one's life' and 'Discrimination'. Age had a mixed effect, while female service users and those with a primary diagnosis of schizophrenia or longer illness duration reported significantly lower capability scores. The results support the feasibility and validity of directly measuring human capabilities for the mentally ill and the potential for applying the approach to outcome measurement.