Development and validation of the self-reported disability status scale (SRDSS) to estimate EDSS-categories
Marco Kaufmann, Anke Salmen, Laura Barin, Milo A. Puhan, Pasquale Calabrese, Christian P. Kamm, Claudio Gobbi, Jens Kühle, Zina‐Mary Manjaly, Vladeta Ajdacic‐Gross, S. Schafroth, Britta Bottignole, Sabin Ammann, Chiara Zecca, Marcus D’Souza, Viktor von Wyl
Abstract
BACKGROUND: Clinician-assessed Expanded Disease Status Scale (EDSS) is gold standard in clinical investigations but normally unavailable in population-based, patient-centred MS-studies. Our objective was to develop a self-reported gait measure reflecting EDSS-categories. METHODS: We developed the self-reported disability status scale (SRDSS) with three categories (≤3.5, 4-6.5, ≥7) based on three mobility-related questions. The SRDSS was determined for 173 persons with MS and validated against clinical EDSS to calculate sensitivity and specificity. RESULTS: Accuracy was 88.4% (153 correctly classified) and weighted kappa 0.73 (0.62-0.84). Sensitivity/specificity-pairs were 94.5%/77.8%, 69.0%/94.7% and 100%/98.2% for SRDSS ≤3.5, 4-6.5 and ≥7, respectively. CONCLUSIONS: Self-reported SRDSS approximates EDSS-categories well and fosters comparability between clinical and population-based studies.