Original article Responsiveness of the 36-item Short Form Health Survey and the Lupus Quality of Life questionnaire in SLE

Objectives. This study aimed to estimate the responsiveness to change of a generic [the 36-item Short Form Health Survey (SF-36)] and a specific health-related quality of life questionnaire [the Lupus Quality if Life questionnaire (LupusQoL)] according to SLE patients ’ self-reported changes in health status. Methods. In a cohort of 185 SLE patients, quality of life (QoL) was measured three times at 3 month intervals by the LupusQoL and SF-36 questionnaires. Anchors for responsiveness were defined by pa-tients ’ global assessment of disease impact according to changes in a visual analogue scale (VAS), a 7-point Likert scale and a 03 scale of five patient-reported symptoms. Mean change and S.D. in worsen-ing and improving patients according to anchors were estimated using mixed models for repeated meas-ures. Standardized response means (SRMs) were calculated in each group. Results. Patients [mean age 39.6 years (S.D. 10.5), mean Safety of Estrogen in Lupus Erythematosus National AssessmentSLEDAI score 2.6 (S.D. 3.5)] answered a total of 515 questionnaires. For the VAS and Likert global anchors, worsening patients showed a significant decrease in all LupusQoL domains except for burden to others, body image and fatigue and all SF-36 domains with low to moderate re-sponsiveness. Improving patients had a significant increase in all LupusQoL domains except for intimat