Development of a New Instrument for Rheumatoid Arthritis
The Cedar-Sinai Health-Related Quality of Life Instrument CSHRQ-RA
Published in: Arthritis Care and Research, v. 49, no. 1, Feb. 7, 2003, p. 78-84
Posted on RAND.org on December 31, 2002
OBJECTIVE: To update and complement existing instruments, the authors 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). METHODS: 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. RESULTS: 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 1). Multi-trait scaling performed on both completed surveys confirmed the 5 sub-scale structure (Cronbach's > 0.87). CONCLUSION: 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.