Peric, S. (35750481700)S. (35750481700)PericVujnic, M. (56079611800)M. (56079611800)VujnicDobricic, V. (22952783800)V. (22952783800)DobricicMarjanovic, A. (56798179100)A. (56798179100)MarjanovicBasta, I. (8274374200)I. (8274374200)BastaNovakovic, I. (6603235567)I. (6603235567)NovakovicLavrnic, D. (6602473221)D. (6602473221)LavrnicRakocevic-Stojanovic, V. (6603893359)V. (6603893359)Rakocevic-Stojanovic2025-06-122025-06-122016https://doi.org/10.1111/ane.12549https://www.scopus.com/inward/record.uri?eid=2-s2.0-84973398794&doi=10.1111%2fane.12549&partnerID=40&md5=0a9e4762c9dd3b0b357c9f27abaca1b2https://remedy.med.bg.ac.rs/handle/123456789/7550Background – Myotonic dystrophy type 1 (DM1) is the most common muscular dystrophy in adults. There is a complete lack of studies that assessed quality of life (QoL) trajectory during time in DM1 cohorts. Aim – To analyze changes of QoL in patients with DM1 during a 5-year follow-up period and to assess responsiveness of the SF-36 questionnaire. Patients and Method – At the baseline, this study comprised 84 DM1 patients, of whom 62 were retested after the mean period of 64.2 ± 3.9 months. Severity of muscular weakness was assessed using the Muscular Impairment Rating Scale (MIRS). Patients completed Serbian version of the SF-36 questionnaire as a measure of health-related QoL. Results – After 5 years, MIRS score of our DM1 patients showed significant progression of 0.5 grade (P < 0.01). All mental subdomains, role physical, and total SF-36 scores significantly improved after 5 years (P < 0.01). Unexpectedly, worsening of muscular weakness from mild to severe was in association with improvement of QoL. Conclusion – QoL improved in our cohort of DM1 patients during a 5-year period despite the progression of the disease. SF-36 should be used with caution as a patient-reported outcome measure in DM1 clinical trials. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltdfollow-upmyotonic dystrophy type 1quality of liferesponsivenessSF-36