To update and complement existing instruments, we developed a multidimensional disease-specific instrument, intended to reflect the impact of rheumatoid arthritis (RA) with modern treatment options on patient's Health-Related Quality of Life (HRQOL).
Items were developed from a systematic review of published HRQOL measures and transcripts of RA patient focus groups. Items were refined by an expert panel and administered to 350 patients for psychometric testing.
The systematic review identified 228 potential items, and the focus group transcripts identified 96 additional items. Expert review and pilot testing resulted in an initial 58-item instrument. Twenty-six items were excluded due to floor/ceiling effects, poor response rates, or high item-item correlations. Factor analysis identified a 5-factor structure (eigenvalues >or=1). Multi-trait scaling performed on both completed surveys confirmed the 5 sub-scale structure (Cronbach's > 0.87).
The CSHQ-RA consists of 33 items that address 5 HRQOL domains, each with high internal consistency. Additional testing will assess the instrument's validity and responsiveness.