Performance of the Patient-Reported Outcomes Measurement Information System-29 in scleroderma: A Scleroderma Patient-centered Intervention Network Cohort Study

Objective. The Patient-Reported Outcomes Measurement Information System (PROMIS)-29 assesses seven health-related quality of life domains plus pain intensity. The objective was to examine PROMIS-29v2 validity and explore clinical associations in patients with SSc. Methods. English-speaking SSc patients in the Scleroderma Patient-centered Intervention Network Cohort from 26 sites in Canada, the USA and the UK completed the PROMIS-29v2 between July 2014 and November 2015. Enrolling physicians provided medical data. To examine convergent validity, hypotheses on the direction and magnitude of correlations with legacy measures were tested. For clinical associations, t-tests were conducted for dichotomous variables and PROMIS-29v2 domain scores. Effect sizes (ESs) were labelled as small ( 0.75). Results. There were 696 patients (87% female), mean (s.d.) disease duration 11.6 (8.7) years, 57% with limited cutaneous subtype. Validity indices were consistent with seven of nine hypotheses (|r| =0.51-0.87, P < 0.001), with minor divergence for two hypotheses. Gastrointestinal involvement was associated with significantly worse outcomes for all eight PROMIS-29v2 domains (moderate or moderate to large ES in six of eight). Presence of joint contractures was associated with significant decrements in seven domains (small or small to moderate ESs). Skin thickening, diffuse cutaneous subtype and presence of overlap syndromes were significantly associated (small or small to moderate ESs) with five or six domains. Conclusion. This study further establishes the validity of the PROMIS-29v2 in SSc and underlines the importance of gastrointestinal symptoms and joint contractures in reduced health-related quality of life.