CROSS-CULTURAL ADAPTATION AND VALIDATION OF THE CHINESE HEALTH ASSESSMENT QUESTIONNAIRE FOR USE IN RHEUMATOID-ARTHRITIS

Objective. The Health Assessment Questionnaire - Disability Index (HAQ ), used as a disability and outcome measurement in rheumatoid arthriti s CRA), has been validated in several languages, but not in Chinese. O ur aim was to validate the Chinese version of HAQ (Chinese-HAQ) to sui t the needs of Chinese speaking patients with RA in an Asian setting. Methods. The original HAQ was modified in the context of Chinese cultu re and translated into Chinese by 2 translators aware of the objective of the questionnaire. The Chinese HAQ was self-administered by 42 pat ients with RA during their routine followup visit and one week later. Results. The test-retest reliability assessed using Spearman's correla tion coefficient was 0.84. Between dimensions measured in the HAQ, the highest test-retest reliability was observed for walking (Spearman co rrelation coefficient r(s) = 0.80) and the lowest was for eating (r(s) = 0.54). The internal consistency of the scale using Cronbach's alpha was high at 0.86. In terms of criterion validity, the Chinese-HAQ sco re was found to correlate well with American College of Rheumatology f unctional status (r(s) = 0.501, p = 0.01). The Chinese-HAQ scores also correlated well with markers of disease activity such as patient's pe rception of pain measured on a visual analog scale (r(s) = 0.55, p < 0 .001), grip strength in mm Hg (r(s) = -0.55, p < 0.001), and physician 's assessment of disease activity (r(s) = 0.59, p < 0.001). Conclusion . The Chinese HAQ is a reliable and valid instrument for studies measu ring disability of patients with RA in Singapore.