OBJECTIVES: Estimate utilities for SSc patients based on EQ-5D and assess its relation with disease specific trial endpoints.

METHODS: EQ-5D-3L (n = 210) was collected in focuSSced phase 3 randomised controlled trial. Utilities were estimated using the Dolan tariff. Pearson correlation was assessed between EQ-5D scores and Modified Rodnan Skin Score (mRSS), Forced Vital Capacity (FVC) and Health Assessment Questionnaire Disability Index (HAQ-DI) Score. Least Square mean utilities per different mRSS, FVC and HAQ levels were estimated and assessed. A mixed model with fixed effects was employed in R® (mlmRev package) for the estimation of utilities, adjusting for baseline utility, age, gender, HAQ-DI and mRSS.

RESULTS: Correlation of EQ-5D was strong only vs. HAQ-DI changes. Mean utilities of 0.72, 0.63, 0.55 and 0.42 were observed in mRSS score categories of <11, 12-22, 23-33 and >34 respectively. Similarly, mean utilities of 0.81, 0.69, 0.59, 0.44 and 0.21 were observed for the HAQ-DI score categories of <0.5, 0.5 – 1.1, 1.2 – 1.6, 1.6 to 2.0 and >2.1 respectively. For FVC >80%, mean utility was 0.67 while for those below 80% utility dropped to 0.60. These utility trends are consistent with the disease severity as reflected in those disease specific measurements. 70% percent of the utility weights observed, were within the range of 0.5 and 0.85, with only 16% of ceiling effect values and 6% negative. Among the coefficients included in the mixed model, only base-case utility and HAQ-DI score were statistically significant. The adjusted estimated utility was 0.648 (St. Error 0.019) in a cohort with average age of 48 years.

CONCLUSIONS: The low adjusted utility observed in this young cohort, indicates the major impact of this disease in the quality of life of these patients. EQ-5D measurements were consistent with the severity of SSc as reflected in the disease specific questionnaires.