Cross-validation and sensitivity to change of EULAR ScleroID as a measure of function and impact of disease in patients with systemic sclerosis.

OBJECTIVE

To determine the distribution of the EULAR SSc Impact of Disease (ScleroID) and its domain questions in very early (Ve), limited (lc) and diffuse cutaneous (dc) subsets, its value in reflecting clinical severity, and to assess its sensitivity to change and minimal clinically important difference (MCID) in a 12-month interval.

METHODS

Patients with ScleroID questionnaires from the observational cohort STRIKE were included in the study. Changes (Δ) were calculated as the difference between 12-month follow-up and compared MCIDs of the other measures.

RESULTS

Data were available for 271 patients, 69 with Ve, 139 lc and 63 dc systemic sclerosis (SSc). Median (IQR) ScleroID scores were progressively higher in the 3 subsets with 2.1 (3.6) for VeSSc, 3.4 (4.4) for lcSSc and 4.7 (4) for dcSSc (p<0.001). ScleroID showed strong content validity against clinical measures. Patients with high disease activity had significantly higher ScleroID scores than low ones (p=0.003). Presence of digital ulcers, pulmonary disease or small intestinal bacterial overgrowth was all reflected in higher scores in their relative domains (p<0.005 for all). Accordingly, ScleroID scores and its relative domains showed high correlations with all other patient-reported outcomes (PROs) (p<0.05). Changes in ScleroID strongly correlated with changes in clinical measures and other PROs with specific thresholds identified for MCID changes in Health Assessment Questionnaire Disability Index, the University of California Los Angeles Scleroderma Clinical Trials Consortium gastrointestinal tract 2.0 and Cochin Hand Function Scale.

CONCLUSION

ScleroID demonstrates strong correlation with validated clinical measures and responsiveness to changes in standard of care, supporting its use in both clinical practice and trials. ScleroID captures the multidimensional burden of SSc regardless of disease subsets.