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 December 31, 2002

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

Read More

Access further information on this document at www3.interscience.wiley.com

This article was published outside of RAND. The full text of the article can be found at the link above.

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.