Ongoing increase in incidence and prevalence of multiple sclerosis in south-eastern Iran: A three decade study

• Published in: Multiple sclerosis and related disorders 2023-03, Vol.71, p.104557-104557, Article 104557
• Main Authors: Moghtaderi, Ali, Shahidi-Pourakbari, Malihe, Izadi, Shahrokh, Khosravi, Alireza, Hashemzehi, Zabihollah
• Format: Article
• Language: English
• Subjects: Epidemiology; Female; Humans; Incidence; Iran; Iran - epidemiology; Longitudinal Studies; Male; Multiple sclerosis; Multiple Sclerosis - epidemiology; Prevalence
• ISSN: 2211-0348; 2211-0356
• DOI: 10.1016/j.msard.2023.104557

•Methods: We rewrote statistical analysis in Methods section again, completely revised and a section about age-standardization added. We described patient selection based on the reviewer comments.•Discussion: we added 2–3 paragraphs about the effect of McDonald criteria and sex ratio in pages 9–11. Two last paragraphs in the previous submission omitted and we wrote about the limitation of the study and small conclusion.•Results: Almost completely changed. Although changes are prominent but we had to reanalyze data according to the reviewer's comments.•References: Some of them are new.•Tables 1 to 3 are merged and there is just one table.•All other tables rewrote according to the new analyses based on the reviewer's comments.•Redrew Figs. 1 and 3 based on new analyses. Prevalence of multiple sclerosis has been increased during the last decades throughout the world. Epidemiological studies could improve our understanding relating to its intrinsic and extrinsic causes. The current study has been conducted to determine the epidemiological features of MS in south-eastern Iran which is a semi-tropical area with different ethnicities. This longitudinal descriptive study was carried out in south-eastern Iran, based on information of MS patients registered at Zahedan University of Medical Sciences database from 1990 to 2020. A total of 1045 cases were enrolled into the study. The age-standardized prevalence ratio of MS increased to 42.2/100,000 population by 2020. These figures showed increasing trends both in females and males and reached to 61.5 and 22.6 per 100,000 population, respectively by the year 2020. Likewise, the total incidence rate grew to its maximum amount of 4.5 in 2015. Female incidence also revealed an upward trend and peaked in 2016 to 6.4 while male incidence rate reached at its highest level of 1.8 in 2009. MS prevalence ratios and incidence rates in south-eastern Iran have been increasing steadily, especially in women during the last three decades. The south-eastern part of Iran should be considered a high-risk region.