To develop an abridged version of the 33-item Cedars-Sinai Health-Related Quality of Life in Rheumatoid Arthritis instrument (CSHQ-RA) and test the validity and reliability of the abridged instrument.
Items from the original 33-item, 5-domain CSHQ-RA were assessed using psychometric and regression analyses of survey responses from 274 patients with rheumatoid arthritis. Items were retained in the final instrument based on statistical analysis and evaluation by an expert panel. Test-retest reliability, internal consistency, convergent and discriminant validity, and ceiling and floor effects were examined for the shortened CSHQ-RA.
Statistical analysis and expert assessment yielded an 11-item instrument including questions in 4 domains. Test-retest reliability and internal consistency were high and the instrument showed good convergent and discriminant validity.
The abridged CSHQ-RA short form is a valid and reliable instrument that can be used to examine the impact of RA on patients' health-related quality of life. Prospective validation in clinical trial settings is warranted.