title: Validation of a rheumatoid arthritis health-related quality of life instrument, the CSHQ-RA.
abstract: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Division of Rheumatology, Cedars-Sinai Health System, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA.
authors.forename: S M
authors.initials: SM
authors.lastname: Russak
authors.forename: C D
authors.initials: CD
authors.lastname: Sherbourne
authors.forename: D P
authors.initials: DP
authors.lastname: Lubeck
authors.forename: H D
authors.initials: HD
authors.lastname: Paulus
authors.forename: C F
authors.initials: CF
authors.lastname: Chiou
authors.forename: N
authors.initials: N
authors.lastname: Sengupta
authors.forename: J
authors.initials: J
authors.lastname: Borenstein
authors.forename: J
authors.initials: J
authors.lastname: Ofman
authors.forename: A
authors.initials: A
authors.lastname: Moadel
authors.forename: M H
authors.initials: MH
authors.lastname: Weisman
mesh_terms: D001172:Arthritis, Rheumatoid / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires