Validation of a Rheumatoid Arthritis Health-Related Quality of Life Instrument, the CSHQ-RA

Published in: Arthritis and Rheumatism, v. 49, no. 6, Dec. 2003, p. 798-803

Posted on RAND.org on January 01, 2003

by Simcha M. Russak, Cathy D. Sherbourne, Deborah P. Lubeck, H. E. Paulus, Chiun-Fang Chiou, Nishan Sengupta, Jeff Borenstein, Joshua J. Ofman, Alyson B. Moadel, Michael Weisman

OBJECTIVE: To test the validity and reliability of a newly developed disease-specific multidimensional quality of life instrument: the Cedars-Sinai Health-Related Quality of Life Instrument (CSHQ-RA). METHODS: A total of 350 rheumatoid arthritis (RA) patients were asked to complete the CSHQ-RA at 2 time points (4 weeks apart). Patients also completed the Medical Outcomes Study Short Form 36 (SF-36) and the Stanford Health Assessment Questionnaire (HAQ) Disability Index (DI) at the second time point. Construct validity was tested, using Pearson's correlations, by comparing subscale scores on the CSHQ-RA to those obtained from the mental component summary (MCS) and physical component summary (PCS) of the SF-36. HAQ DI scores were used to assess the discriminant validity of the CSHQ-RA. Intraclass correlation coefficients (ICCs) were used to assess test-retest reliability. RESULTS: Response rates for the first and second survey were 83% (291) and 93% (276), respectively; 84% of respondents were women, and mean age was 57 years. Mean scores +/- SDs on instruments were: HAQ 0.73 +/- 0.69; MCS 49 +/- 12; and PCS 33 +/- 11. Pearson's correlations between the CSHQ-RA subscale scores and the SF-36 scores ranged from 0.55 to 0.76 (P < 0.001). Analysis of variance indicate that scores on the CSHQ-RA discriminated between levels of physical disability as measured by the HAQ (P < 0.001). Test-retest reliability was demonstrated in the instrument's subscale scores (ICC 0.70-0.90). CONCLUSION: These results support the construct validity, discriminant validity, and reliability of the CSHQ-RA as a measure that captures the impact of RA on patients' health-related quality of life.

This report is part of the RAND Corporation External publication series. Many RAND studies are published in peer-reviewed scholarly journals, as chapters in commercial books, or as documents published by other organizations.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.