healthcare Article A Greek Validation Study of the Multiple Sclerosis Work Difficulties Questionnaire-23 Christos Bakirtzis 1, * ,† , Artemios Artemiadis 2,† , Elli Nteli 1 , Marina Kleopatra Boziki 1 , Maria-Valeria Karakasi 3 , Cynthia Honan 4 , Lambros Messinis 5 , Grigorios Nasios 6 , Efthimios Dardiotis 7 and Nikolaos Grigoriadis 1   Citation: Bakirtzis, C.; Artemiadis, A.; Nteli, E.; Boziki, M.K.; Karakasi, M.-V.; Honan, C.; Messinis, L.; Nasios, G.; Dardiotis, E.; Grigoriadis, N. A Greek Validation Study of the Multiple Sclerosis Work Difficulties Questionnaire-23. Healthcare 2021, 9, 897. https://doi.org/10.3390/ healthcare9070897 Academic Editor: Konrad Rejdak Received: 25 May 2021 Accepted: 13 July 2021 Published: 15 July 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Multiple Sclerosis Center, Second Department of Neurology, Aristotle University of Thessaloniki, GR 54124 Thessaloniki, Greece; nteli.elli@gmail.com (E.N.); bozikim@auth.gr (M.K.B.); ngrigoriadis@auth.gr (N.G.) 2 Faculty of Medicine, University of Cyprus, Nicosia CY 2029, Cyprus; artemiadis.artemios@ucy.ac.cy 3 Third University Department of Psychiatry, AHEPA University General Hospital, GR 54124 Thessaloniki, Greece; valeria28289@hotmail.gr 4 School of Psychological Sciences, College of Health and Medicine, University of Tasmania, TAS 7250 Launceston, Australia; cynthia.honan@utas.edu.au 5 Neuropsychology Section, University Hospital of Patras, GR 26504 Patras, Greece; lmessinis@upatras.gr 6 Department of Speech and Language Therapy, University of Ioannina, GR 45110 Ioannina, Greece; nasios@uoi.gr 7 Department of Neurology, University of Thessaly, GR 41500 Larisa, Greece; edar@med.uth.gr * Correspondence: cbakirtzis@auth.gr; Tel.: +30-2310-994-665 † Equally contributing first authors. Abstract: The Multiple Sclerosis Work Difficulties Questionnaire-23 (MSWDQ-23) is a self-report instrument developed to assess barriers faced by People with Multiple Sclerosis (PwMS) in the workplace. The aim of this study was to explore the psychometric properties of the Greek version of the MSWDQ-23. The study sample consisted of 196 PwMS, all currently working in part- or full-time jobs. Participants underwent clinical examination and cognitive screening with the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) and completed self-report measures of fatigue, psychological functioning, and quality of life, along with the MSWDQ-23 questionnaire. Confirmatory Factor Analysis (CFA) was performed, and goodness-of-fit measures were used to evaluate construct validity. Convergent validity was checked by correlating MSWDQ-23 scores with study measures. Cronbach’s alpha value was produced to assess internal consistency. CFA yielded a model with a fair fit confirming the three-factor structure of the instrument. Higher work difficulties were associated with higher Expanded Disability Status Scale (EDSS) scores, poorer cognitive function, more fatigue, stress, anxiety, and depression, and poorer health status, supporting the convergent validity of MSWDQ-23. Internal consistency (Cronbach’s alpha = 0.94) and test– retest reliability (ICC = 0.996, 95%, CI = 0.990–0.998) were excellent. The Greek MSWDQ-23 can be considered a valid patient-reported outcome measure and can be used in interventions aiming to improve the vocational status of PwMS. Keywords: multiple sclerosis; employment; patient-reported outcome; MSWDQ-23; validation 1. Introduction Multiple Sclerosis (MS) is the most common demyelinating and neurodegenerative disease of the central nervous system in young adults [1]. Loss of productivity is common in People with MS (PwMS) and is strongly related to higher levels of physical disability [2,3], reduced subcortical and cortical gray matter volumes [4], cognitive impairment [5], and higher self-perceived fatigue, anxiety, and mood [6,7]. According to an international survey conducted in Europe with more than 13,000 participants, an estimated 50% of working-age PwMS are unemployed, although significant variability of employment rates is observed Healthcare 2021, 9, 897. https://doi.org/10.3390/healthcare9070897 https://www.mdpi.com/journal/healthcare