Temporal Incidence and Prevalence Trends of Multiple Sclerosis in Markazi Province, Iran.

BACKGROUND

The epidemiology of multiple sclerosis (MS) exhibits significant variability all over the world. Additionally, the incidence and prevalence of the disease are geographically diverse in the different provinces of Iran.

OBJECTIVES

Due to the lack of a research about the epidemiology of MS in the Markazi province of Iran, the present study aimed to estimate its prevalence and incidence in this province.

METHODS

This cross-sectional register study was conducted according to the data related to the MS Society of Markazi province. The inclusion criteria were definite MS during 2010-2019, residence in Markazi province, and membership in the MS society of Markazi province. The annual incidence and prevalence of MS (per 100,000 person-years) were computed by sex and age groups. Further, age-standardized prevalence and incidence rates were calculated based on the Iranian population. A gamma regression model with log link was utilized for comparing the rates over time statistically. The prevalence and incidence rates were computed by using Excel, and R 4.0.5 was applied to fit the gamma model.

RESULTS

In the study, the total number of MS cases was 1,391, among whom 1,098 (78.9%) and 293 (21.1%) were females and males, respectively. The onset of MS occurred at the mean (S.D) age of 31.76 (8.98) years with a female/male ratio of 3.75. During the study period (2010-2019), the incidence rate of the disease was on the decline, while the prevalence rate elevated, by indicating a rising trend in MS prevalence in both sexes.

CONCLUSION

The results represented the decreasing and increasing trend of the incidence and prevalence of MS in Markazi province over the recent years. The province is one of the regions with a high prevalence and incidence rate of MS compared to the national and global statistical data.