Development and validation of the self-reported disability status scale (SRDSS) to estimate EDSS-categories

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.

Keywords: EDSS; Patient reported outcome; Proxy measure; Registries; Self-report.

Conflict of interest statement

Declaration of Conflict of Interests AS received speaker honoraria and/or travel compensation for activities with Almirall Hermal GmbH, Biogen, Merck, Novartis, Roche, and Sanofi Genzyme, none related to this work. CG: The Department of Neurology, Regional Hospital Lugano (EOC), Lugano, Switzerland, receives financial support from Teva, Merck Serono, Biogen, Genzyme, Roche, Celgene, Bayer, and Novartis. The submitted work is not related to these agreements. CPK has received honoraria for lectures as well as research support from Biogen, Novartis, Almirall, Bayer Schweiz AG, Teva, Merck, Sanofi Genzyme, Roche, Eli Lilly, Celgene and the Swiss MS Society (SMSG). CZ has received compensation for consulting services and for speaking activities from Biogen, Merck, Mylan, Novartis, Teva, Roche, and Sanofi Genzyme. JK's institution (University Hospital Basel) received and used exclusively for research support consulting fees from Biogen, Novartis, Protagen AG, Roche, and Teva; speaker fees from Biogen, Genzyme, Novartis, Roche, and the Swiss Multiple Sclerosis Society; travel expenses from Merck Serono, Novartis, and Roche; grants from Bayer AG, Biogen, the ECTRIMS Research Fellowship Programme, Genzyme, Merck, Novartis, Roche, the Swiss Multiple Sclerosis Society, the Swiss National Research Foundation (320,030_160,221), and the University of Basel. MDS has received travel support from Bayer AG, Biogen, Teva Pharmaceuticals and Sanofi Genzyme and research support from the University Hospital Basel. PC has received honoraria for speaking at scientific meetings, serving at scientific advisory boards and consulting activities from: Abbvie, Actelion, Almirall, Bayer-Schering, Biogen Idec, EISAI, Disease burden of MS Genzyme, Lundbeck, Merck Serono, Novartis, Pfizer, Teva, and Sanofi-Aventis; his research is also supported by the Swiss Multiple Sclerosis Society, the Swiss National Research Foundation and the SOFIA Foundation. BB, LB, MAP, MK, SAS, SA, VA, VvW and ZMM declare that there is no conflict of interest.

Copyright © 2020 The Author(s). Published by Elsevier B.V. All rights reserved.