Validation of the MOS SF-36 for quality of life assessment of patients with systemic lupus erythematosus in Singapore

• Published in: Journal of rheumatology Vol. 26; no. 1; p. 97
• Main Authors: Thumboo, J, Fong, K Y, Ng, T P, Leong, K H, Feng, P H, Thio, S T, Boey, M L
• Format: Journal Article
• Language: English
• Published: Canada 01.01.1999
• Subjects: Cohort Studies; Cross-Over Studies; Demography; Evaluation Studies as Topic; Health Care Surveys; Humans; Lupus Erythematosus, Systemic - physiopathology; Lupus Erythematosus, Systemic - psychology; Outcome Assessment (Health Care); Quality of Life; Reproducibility of Results; Singapore; Singapore
• ISSN: 0315-162X

To assess the reliability and construct validity of the Medical Outcomes Study Short Form 36 Health Survey (SF-36) in a multiracial cohort of Asian patients with lupus in Singapore. A cross sectional study was performed on 118 English speaking patients with lupus attending a specialist rheumatology unit between March and August 1996. Patients completed a questionnaire containing the UK standard version of the SF-36 twice within a 14 day period. All patients were assessed for disease activity using the British Isles Lupus Assessment Group score (BILAG), and for disease related damage using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage index (DI). Relationships between SF-36, BILAG, and DI scores were studied using Spearman's rank correlation. Internal consistency of the SF-36 was assessed using Cronbach's alpha, and stability using the repeatability coefficient of Bland and Altman. SF-36 subscales showed high internal consistency, with Cronbach's alpha coefficient ranging from 0.84 to 0.94. Test-retest reliability was acceptable, with Spearman's rank correlation >0.70 for all subscales except role-physical, and mean differences in test scores of <2 points for 5 of 8 subscales. SF-36 subscale scores were weakly correlated with BILAG scores (Spearman's p -0.37 to 0.15) and SLICC/ACR DI scores (Spearman's p -0.25 to 0.23), suggesting divergent construct validity of the SF-36. These data suggest the SF-36 is a reliable and valid measure of the quality of life of patients with lupus in Singapore.