To validate the psychometric properties of the Chinese Health Assessment Questionnaire (HAQ) for use in rheumatoid arthritis (RA) patients in China.
The psychometric properties of the HAQ were validated by interviewing subjects with a questionnaire battery containing the HAQ, EQ-5D, and Short Form 12 (SF-12). Reliability was assessed by Cronbach's alpha, construct validity by assessing a priori hypotheses, and discriminative validity by discriminating subjects in different groups, respectively. To assess the applicability of HAQ in different regions, subgroup analyses were conducted for south and north China, respectively.
Questionnaires were administered to a consecutive sample of 133 RA patients. Cronbach's alpha showed a strong reliability among all the items. In particular, the internal reliability was higher when excluding the items about the use of aids and devices: 0.987 when excluding versus 0.963 when including. Construct validity was supported by achieving both of the a priori hypotheses based on correlations between the HAQ scores and scales of EQ-5D and SF-12. Overall, HAQ scores were important inferential factors for Global Functional Status in RA, which indicated good discriminative validity. The validation results are generally consistent between subgroups from north and south China.
The Chinese HAQ demonstrated good acceptability and psychometric properties in RA patients from China. Two possible improvements for better use and interpretation of the patient-reported outcomes of RA patients in China could be to cross-culturally adapt the items about the use of aids and devices and joint use of mental health measurements together with HAQ in future studies.