Preliminary Validation of the Digital Ulcer Clinical Assessment Score in Systemic Sclerosis

Abstract

Objective.To date, “healed/non-healed” and clinical judgment are the only available assessment tools for digital ulcers (DU) in patients with systemic sclerosis (SSc). The aim of our study is to examine a preliminary composite DU clinical assessment score (DUCAS) for SSc for face, content, and construct validity.Methods.Patients with SSc presenting at least 1 finger DU were enrolled and assessed with the Health Assessment Questionnaire–Disability Index, Cochin scale, visual analog scale (VAS) for DU-related pain, patient global DU status, and global assessment as patient-reported outcomes (PRO), and physician VAS for DU status (phyGDU) as an SSc-DU expert physician/nurse measure. The DUCAS included 7 DU-related variables selected by a committee of SSc DU experts and weighted on a clinical basis. Face validity was examined by consensus and partial construct validity was tested through convergent correlation with other measures of hand function, using Spearman’s correlations. A range of patients with SSc was examined. A linear regression model with backward stepwise analysis was used to determine the relationship of individual variables with the primary clinical parameter, phyGDU.Results.Forty-four patients with SSc (9 males, mean age 55 ± 15 yrs, mean disease duration 9.9 ± 5.8 yrs) were enrolled in the study. Overall DUCAS showed significant positive correlations with all abovementioned PRO (r > 0.4, p < 0.01). When all scores and scales were modeled, only DUCAS significantly predicted phyGDU (r = 0.59, R2 = 0.354, Akaike information criterion = 385.4).Conclusion.Preliminarily, we suggest that the DUCAS may be a new clinical score for SSc-related DU, having face and content validity and convergent/divergent correlations (construct validity). These early data suggest that this score deserves further evaluation.

Psychometric validation of the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU®) patient-reported outcome instrument

“…The HDISS-DU could be used in parallel with new clinical outcome measures currently in development, such as the DU clinical assessment score (DUCAS) for SSc [29]. The DUCAS is an objective, physician-defined measure that provides a composite clinical score for SSc-DUs; it was not developed with any patient input [29].…”

Gaining the Upper Hand on Systemic Sclerosis Digital Ulcers

“…To address this need, in this issue of The Journal, Bruni, et al present the Digital Ulcer Clinical Assessment Score (DUCAS) in systemic sclerosis 10 . This outcome measure, designed for use in therapeutic trials, is the first composite measure developed to clinically assess DU.…”

“…This outcome measure, designed for use in therapeutic trials, is the first composite measure developed to clinically assess DU. Using consensus methodology, drawing upon the knowledge and experience of 8 experts in SSc-associated DU, the authors identified 7 domains important in the assessment of the burden of DU (Bruni, et al, Table 1) 10 . The final score is weighted across all 7 domains, with the weighting of each item determined by expert consensus, to give a total possible score of 19.5.…”

“…As a first step toward the validation of DUCAS according to the Outcome Measures in Rheumatology (OMERACT) Filter of truth, discrimination, and feasibility 11 , Bruni, et al have performed a small validation study of 44 patients from a single center, testing the content and construct validity of DUCAS 10 . The convergent and divergent correlation coefficients of DUCAS with other clinical outcome measures were evaluated, including DU-specific patient-reported outcomes (PRO).…”

“…Assessment of both the presence and number of new DU combines to account for a maximum possible score of 4 out of a total 19.5 points of the DUCAS (Bruni, et al, Table 1) 10 . All DUCAS in the study by Bruni, et al were calculated by a single physician at a single study visit.…”