OBJECTIVE: This study reassessed the psychometric characteristics of the original 33-item CSHQ-RA instrument using a representative population of RA patients from 55 sites across the US. METHODS: Three hundred seven of 309 screened patients from a 24-week multicenter, open-label, single arm study of RA patients receiving anakinra completed the 33-item CSHQ-RA, the Medical Outcomes Study Short Form-36 (MOS SF-36) and the Stanford Health Assessment Questionnaire (HAQ) Disability Index. Data at screening and baseline were used to examine the convergent validity, discriminant validity, internal consistency, and test-retest reliability. Convergent validity was tested, using Pearson's correlations, by comparing total and subscale scores on the CSHQ-RA to those from the Mental and Physical Component Summary (MCS and PCS) of the MOS SF-36 and HAQ. ANOVA and Kruskal-Wallis tests were used to assess the discriminant validity of the CSHQ-RA. Internal consistency was measured by Cronbach's alpha coefficient. Test-retest reliability was assessed using intraclass correlation coefficients (ICCs). RESULTS: Response rate at baseline was 95% (291). Eighty-one percent of respondents were female; mean age was 52 years (±12); mean duration with RA was 10.8 years ( ± 10.4). At baseline, mean scores on instruments were HAQ 1.5 ( ± 0.7), MCS 37.9 ( ± 10.9), and PCS 31.2 (± 8.3). Pearson's correlations between the CSHQ-RA and the MOS SF-36 and HAQ scores ranged from -0.33 to -0.73 (P <0.0001) and 0.39 to 0.76 (P <0.0001), respectively. The difference in scores on the CSHQ-RA of patients with different levels of physical disability as measured by the HAQ was statistically significant (P <0.0001). Cronbach's alpha coefficients were = 0.9 indicating good internal consistency. Test-retest reliability was demonstrated in the instrument's subscales with ICCs ranging from 0.82 to 0.94. CONCLUSIONS: These results support the validity and reliability of the original CSHQ-RA when tested in a representative patient population. Research to assess responsiveness and clinically significant change of the CSHQ-RA is underway.