The reliability, validity and sensitivity to change of the Chinese version of SF-36 in oriental patients with rheumatoid arthritis.

OBJECTIVE: To assess the reliability, validity and sensitivity to change of a Chinese version of the 36-item Short-Form Health Survey (SF-36) in Chinese-speaking patients with rheumatoid arthritis (RA) in Singapore. METHODS: The psychometric properties of the Chinese Hong Kong standard version of the SF-36 were assessed in 401 RA patients. The construct validity of the Chinese SF-36 was assessed by comparison with the American College of Rheumatology (ACR) functional status, a validated Chinese Health Assessment Questionnaire (C-HAQ) and markers of RA activity and severity. RESULTS: The overall Cronbach's coefficient alpha was 0.921, reflecting excellent internal consistency. The instrument showed reasonable test-retest reliability except in the social functioning (SF) subscale. There was a significant ceiling effect in the role physical (RP), SF and role emotional (RE) subscales and a floor effect in the RP and RE subscales. Physical function (PF) and SF were strongly correlated with C-HAQ and patient's assessment of RA activity [Pearson's correlation coefficient (r) ranging from -0.41 to -0.53] and moderately correlated with ACR functional status (r = -0.35 and -0.3, respectively). Weak correlations were also found between the Chinese SF-36 and markers of RA activity, deformed joint count and radiographic damage. PF and SF were the subscales most responsive to change in quality of life (QOL). CONCLUSION: The Chinese SF-36 showed reasonable reliability, criterion validity and responsiveness with limitations in certain subscales. Overall, the physical domains and PF in particular may be the most ideal psychometric measures of QOL in RA.

Development and preliminary validation of a systemic lupus erythematosus-specific quality-of-life instrument (SLEQOL).

OBJECTIVES: Systemic lupus erythematosus (SLE), a chronic illness with an unpredictable and variable course, profoundly affects the quality of life (QOL). General health questionnaires are used to assess QOL in SLE, but a disease-specific instrument could offer enhanced responsiveness and content validity. We detail the steps we took to develop and validate a new SLE-specific QOL instrument, SLEQOL. METHODS: Rheumatology professionals nominated items that they felt were important determinants of QOL of SLE patients. One hundred SLE patients were asked to assess the importance and frequency of occurrence of these items and to suggest those that had not been listed. Item reduction was performed using Rasch model and factor analyses to create a new questionnaire in English. This final questionnaire was administered to a cohort of 275 patients to study its psychometric properties. RESULTS: Fifty-one items covering a wide range of QOL concerns were identified. The patients' responses led to the elimination of 11. The new questionnaire of 40 items was found to have Cronbach's alpha of 0.95 and to consist of eight domains covering physical, mental and social QOL issues. It has good test-retest reliability, poor to fair cross-sectional correlation with the SF-36, with poor correlation with lupus activity or damage indices. The SLEQOL was more responsive to change than the SF-36. CONCLUSIONS: We have developed a new 40-item SLEQOL in English and showed that it is valid for use in SLE patients in Singapore. It offers better content validity and responsiveness to change than the SF-36.

Why lupus patients use alternative medicine.

It is unclear whether patients use alternative medicine because of psychological distress associated with their disease or philosophical congruence with this form of treatment. Therefore, we have studied why patients with systemic lupus erythematosus (SLE) employ alternative medicine. We interviewed 192 consecutive Chinese SLE outpatients in a tertiary-care rheumatology centre. We recorded their demographic data, usage of traditional Chinese medication, the predominant form of alternative medicine in this group, and the Rheumatology Attitudes Index score. We distinguished two types of alternative medicine users: those who use it with intent to treat SLE (disease-specific users; 73 users, 38.0%) and those who use it for cultural and other reasons (general-health users; 55 users, 28.6%). Users regarded their disease as mild compared to nonusers. Disease-specific users were distinguished from nonusers by having Chinese as a first language (odds ratio, 2.14-8.83), greater learned helplessness (odds ratio, 1.02-1.29), and an earlier age of diagnosis (odds ratio, 0.92-0.98 for older age). In conclusion, the majority of our lupus patients have used alternative medicine. The motivations of general-health and disease-specific users are different. The patients' first language and perceived helplessness influenced the disease-specific users, while general-health users were subject to neither of these.

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 arthritis (RA), has been validated in several languages, but not in Chinese. Our aim was to validate the Chinese version of HAQ (Chinese-HAQ) to suit the needs of Chinese speaking patients with RA in an Asian setting. METHODS: The original HAQ was modified in the context of Chinese culture and translated into Chinese by 2 translators aware of the objective of the questionnaire. The Chinese HAQ was self-administered by 42 patients with RA during their routine followup visit and one week later. RESULTS: The test-retest reliability assessed using Spearman's correlation coefficient was 0.84. Between dimensions measured in the HAQ, the highest test-retest reliability was observed for walking (Spearman correlation coefficient rs=0.80) and the lowest was for eating (rs=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 score was found to correlate well with American College of Rheumatology functional status (rs=0.501, p=0.01). The Chinese-HAQ scores also correlated well with markers of disease activity such as patient's perception of pain measured on a visual analog scale (rs=0.55, p < 0.001), grip strength in mm Hg (rs=-0.55. p < 0.001 ), and physician's assessment of disease activity (rs=0.59, p < 0.001). CONCLUSION: The Chinese HAQ is a reliable and valid instrument for studies measuring disability of patients with RA in Singapore.