Validation of a Chinese version of the Medical Outcomes Study Family and Marital Functioning Measures in patients with SLE

The objective was to validate a Chinese translation of the Medical Outcomes Study Family and Marital Functioning Measures (FFM and MFM) in patients with systemic lupus erythematosus (SLE). Chinese-speaking SLE patients (n = 69) completed a self-administered questionnaire containing the FFM and MFM and assessing demographic and socio-economic status twice within a 2 week period. SLE activity, disease-related damage and quality of life were assessed using the BILAG, SLICC/ACR Damage Index and SF-36 Health Survey, respectively. Scale psychometric properties were assessed through factor analysis, Cronbach's alpha, quantifying test-retest differences and known-groups construct validity. Factor analysis identified 1 factor corresponding to the FFM and 2 factors corresponding to the MFM. Internal consistency for the FFM was excellent (alpha = 0.92) while that for the MFM was acceptable (alpha = 0.62). Mean (s.d.) test-retest differences were 0.06 (1.54) points for the FFM and 0.03 (2.08) points for the MFM. 11 and 10 of 13 a priori hypotheses relating the FFM and MFM, respectively, to demographic, disease and quality of life variables were confirmed, supporting the construct validity of these scales. The Chinese FFM and MFM are valid and reliable measures of family and marital functioning in Chinese-speaking SLE patients, with psychometric properties very similar to the source English version.