Objective: To assess health values in subjects with systemic sclerosis (SSc) and determine variability explained by demographics, clinical factors, health status, and disease severity.
Methods: We interviewed 107 individuals with SSc who attended national and local Scleroderma Foundation meetings in 2005. Health status was measured using the Short Form 36 (SF-36) Physical Component Summary (PCS; range 0-100) and Mental Component Summary (MCS; range 0-100), the Center for Epidemiologic Studies Depression Scale (CES-D; range 0-60), and the Health Assessment Questionnaire (HAQ) disability index (DI; range 0-3). Disease severity was assessed using a visual analog scale (VAS; range 0-150). Health value measures included the 0-100 health rating scale (RS), standard gamble (SG; range 0.0-1.0), and time trade-off (TTO; range 0.0-1.0). We performed univariate analyses to compare scores between participants with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc), and multivariable analyses for 3 outcome measures: RS, SG, and TTO, controlling for demographics, type of SSc, health status, and disease severity.
Results: Of the 107 participants, 48 had dcSSc and 59 had lcSSc. Ninety-seven were women and 83 were white. The median scores for the PCS, MCS, and HAQ DI were 36.9, 45.5, and 0.9, respectively. Fifty-five subjects had significant depressive symptoms (CES-D score >or=16). The median RS, SG, and TTO scores were 62, 0.83 (indicating a willingness to accept up to a 17% risk of immediate death in exchange for perfect health), and 0.88 (indicating a willingness to give up a median of 12% of life expectancy in exchange for perfect health), respectively. Subjects with dcSSc had lower RS scores but higher SG scores (corresponding to a willingness to accept only a smaller risk of death) than subjects with lcSSc. TTO scores were similar in the 2 groups. Health values were variably related to factors such as demographics, VAS score, disease classification, and SF-36 PCS and MCS scores (R(2) = 0.22, 0.23, and 0.66 for the SG, TTO, and RS models, respectively).
Conclusion: Individuals with dcSSc have lower health ratings but higher SG health values than individuals with lcSSc. These findings have implications for decision analysis and cost-effectiveness analysis.