The reliability and construct validity of the RAQoL: a rheumatoid arthritis-specific quality of life instrument

The present study was designed to test the psychometric properties of theRAQoL, a rheumatoid arthritis (RA)-specific quality of life (QoL)instrument. All stages of the development were conducted simultaneously inThe Netherlands and the UK. The content of the draft measure was derivedfrom qualitative interviews with RA patients in both countries. The finalversion of the RAQoL has 30 items with a 'yes'/'no' response format andtakes approximately 6 min to complete. Both language versions have highinternal consistency and test-retest reliability (> 0.9), and goodsensitivity to discriminate between groups with various disease activityand severity. Given the excellent psychometric properties of the newinstrument, it will prove to be a valuable tool for assessing quality oflife in clinical trials and for monitoring patients in routine clinicalpractice.