The Scleroderma Patient-Centered Intervention Network Cohort: baseline clinical features and comparison with other large scleroderma cohorts

Objectives. The Scleroderma Patient-centered Intervention Network (SPIN) Cohort is a web-based cohort designed to collect patient-reported outcomes at regular intervals as a framework for conducting trials of psychosocial, educational, self-management and rehabilitation interventions for patients with SSc. The aim of this study was to present baseline demographic, medical and patient-reported outcome data of the SPIN Cohort and to compare it with other large SSc cohorts. Methods. Descriptive statistics were used to summarize SPIN Cohort characteristics; these were compared with published data of the European Scleroderma Trials and Research (EUSTAR) and Canadian Scleroderma Research Group (CSRG) cohorts. Results. Demographic, organ involvement and antibody profile data for SPIN (N= 1125) were generally comparable with that of the EUSTAR (N= 7319) and CSRG (N= 1390) cohorts. There was a high proportion of women and White patients in all cohorts, though relative proportions differed. Scl70 antibody frequency was highest in EUSTAR, somewhat lower in SPIN, and lowest in CSRG, consistent with the higher proportion of interstitial lung disease among dcSSc patients in SPIN compared with in CSRG (48.5 vs 40.3%). RNA polymerase III antibody frequency was highest in SPIN and remarkably lower in EUSTAR (21.1 vs 2.4%), in line with the higher prevalence of SSc renal crisis (4.5 vs 2.1%) in SPIN. Conclusion. Although there are some differences, the SPIN Cohort is broadly comparable with other large prevalent SSc cohorts, increasing confidence that insights gained from the SPIN Cohort should be generalizable, although it should be noted that all three cohorts include primarily White participants.