Psychometric evaluation of the 5-item Medication Adherence Report Scale questionnaire in persons with multiple sclerosis

Jožef, Maj (author), Locatelli, Igor (author), Brecl Jakob, Gregor (author), Savšek, Lina (author), Šurlan Popović, Katarina (author), Špiclin, Žiga (author), Rot, Uroš (author), Kos, Mitja (author)

The 5-item Medication Adherence Report Scale (MARS-5) is a reliable and valid questionnaire for evaluating adherence in patients with asthma, hypertension, and diabetes. Validity has not been determined in multiple sclerosis (MS). We aimed to establish criterion validity and reliability of the MARS-5 in persons with MS (PwMS). Our prospective study included PwMS on dimethyl fumarate (DMF). PwMS self-completed the MARS-5 on the same day before baseline and follow-up brain magnetic resonance imaging (MRI) 3 and 9 months after treatment initiation and were graded as highly and medium adherent upon the 24-cutoff score, established by receiver operator curve analysis. Health outcomes were represented by relapse occurrence from the 1st DMF dispense till follow-up brain MRI and radiological progression (new T2 MRI lesions and quantitative analysis) between baseline and follow-up MRI. Criterion validity was established by association with the Proportion of Days Covered (PDC), new T2 MRI lesions, and Beliefs in Medicines questionnaire (BMQ). The reliability evaluation included internal consistency and the test-retest method. We included 40 PwMS (age 37.6 ± 9.9 years, 75% women), 34 were treatment-naive. No relapses were seen during the follow-up period but quantitative MRI analysis showed new T2 lesions in 6 PwMS. The mean (SD) MARS-5 score was 23.1 (2.5), with 24 PwMS graded as highly adherent. The higher MARS-5 score was associated with higher PDC (b = 0.027, P<0.001, 95% CI: (0.0134–0.0403)) and lower medication concerns (b = -1.25, P<0.001, 95% CI: (-1.93-(-0,579)). Lower adherence was associated with increased number (P = 0.00148) and total volume of new T2 MRI lesions (P = 0.00149). The questionnaire showed acceptable internal consistency (Cronbach α = 0.72) and moderate test-retest reliability (r = 0.62, P < 0.0001, 95% CI: 0.33–0.79). The MARS-5 was found to be valid and reliable for estimating medication adherence and predicting medication concerns in persons with MS.

• Language: English
• Keywords: Medication Adherence Report Scale (MARS-5), dimethyl fumarate, multiple sclerosis, new T2 MRI lesions, Proportion of Days Covered (PDC), Beliefs in Medicines questionnaire (BMQ), validation, consistency, test-retest
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering; MF - Faculty of Medicine; FFA - Faculty of Pharmacy
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: 13 str.
• Numbering: Vol. 19, issue 3, art. e0294116
• PID: 20.500.12556/RUL-173353
• UDC: 616.832-004
• ISSN on article: 1932-6203
• DOI: 10.1371/journal.pone.0294116
• COBISS.SI-ID: 188641539
• Publication date in RUL: 16.09.2025

Record is a part of a journal

• Title: PloS one
• Publisher: PLOS
• ISSN: 1932-6203
• COBISS.SI-ID: 2005896

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: lestvica poročanja o upoštevanju zdravil (MARS-5), dimetil fumarat, multipla skleroza, nove T2 MRI lezije, razmerje pokritih dni (PDC), vprašalnik o prepričanjih v zdravila (BMQ), validacija, konsistenca, test ponovnega testiranja

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P1-0189
• Name: Farmacevtska tehnologija: od dostavnih sistemov učinkovin do terapijskih izidov zdravil pri otrocih in starostnikih

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0232
• Name: Analiza biomedicinskih slik in signalov