EDITED BY Ann Van de Winckel, University of Minnesota Twin Cities, United States REVIEWED BY Charles Sebiyo Batcho, Laval University, Canada Peter Hagell, Kristianstad University, Sweden *CORRESPONDENCE Alan Tennant a.tennant@leeds.ac.uk RECEIVED 19 April 2023 ACCEPTED 03 July 2023 PUBLISHED 17 July 2023 CITATION Tennant A and Küçükdeveci AA (2023) Application of the Rasch measurement model in rehabilitation research and practice: early developments, current practice, and future challenges. Front. Rehabil. Sci. 4:1208670. doi: 10.3389/fresc.2023.1208670 COPYRIGHT © 2023 Tennant and Küçükdeveci. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. Application of the Rasch measurement model in rehabilitation research and practice: early developments, current practice, and future challenges Alan Tennant 1 * and Ayse A. Küçükdeveci 2 1 Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, United Kingdom, 2 Department of Physical Medicine and Rehabilitation, Faculty of Medicine, Ankara University, Ankara, Turkey The application of the Rasch measurement model in rehabilitation is now well established. Both its dichotomous and polytomous forms provide for transforming ordinal scales into interval-level measures, consistent with the requirements of fundamental measurement. The growth of applying the model in rehabilitation spans 30 years, during which both the protocol has steadily developed and several software packages have emerged that provide for analysis, together with the “R” language that has an increasing set of codes for applying the model. This article reviews that development and highlights current practice requirements, including those for providing the relevant information for the methods, and what is expected of the analysis. In addition, this provides a worked example and looks at the remaining issues and current developments of its application. KEYWORDS Rasch, rehabilitation, guidance, history, stroke 1. Introduction It has been over 30 years since Rasch analysis was introduced to rehabilitation, based on the original work by Georg Rasch, a Danish mathematician and statistician. Its application in rehabilitation to date has been prolific, with almost 1,500 manuscripts indexed in PUBMED with “Rasch” as a title or abstract together with “rehabilitation”. These range from early works examining existing scales, through the development of new scales, to the development of item banks for computer adaptive testing (CAT) (1–3). Why then should it be so popular in the context of assessment and measuring outcomes in rehabilitation? As such, it seems appropriate to review what exactly the model is, how it came to be applied in rehabilitation, and what the current practice and issues that arise are, together with possible future developments. 1.1. What is the Rasch model? In its simplest (dichotomous) form, it is a probabilistic model that postulates that the probability of obtaining a correct response to a test item (e.g. correct/incorrect) is a TYPE Methods PUBLISHED 17 July 2023 | DOI 10.3389/fresc.2023.1208670 Frontiers in Rehabilitation Sciences 01 frontiersin.org