Abstract| Volume 37, 101559, January 2020

Epidemiology of MS in Tehran Province, Iran: A Population- Based Study

      There is a significant increase of Multiple Sclerosis (MS) in Asia, special in Iran. Familial recurrence studies in MS are useful to identify the correlated effects in etiology of the disease.
      This is a cross-sectional study based on Iranian MS Society data from 1999 to 2018 with the aim of estimating incidence, prevalence and assessing associations among most important variables related to familial MS (gender, age at disease onset, types of MS and familial history). Multiple regressions were used to indicate the predictors of MS via SPSS.
      Among 21580 MS subjects, the crude incidence and prevalence rate was 6.93 and 151.3 per 100000 populations in 2018 respectively. Completely 16187 (75%) were female and female to male ratio was 3:1.Mean age at disease onset was 28.82 years old, 9.7% of the population had early onset MS (<=18 years old). Female gender was a strong significant predictor for onset age (p<0.001). 749 (14.4%) of male patients and 2066 (13.1%) of female patients had a history of familial MS which was significantly different between them, p value=0.017, (OR=1.11; 95% CI=1.02, 1.22). Crude odds ratio for familial recurrence of MS in first degree of relatives was significantly different among genders (OR=1.30; 95% CI=1.12, 1.5). The age standardized prevalence rate of MS was estimated 54.1 (95%CI: 53.6-54.6) among males and 174.5 (95%CI: 173.6-175.4) per 100,000 among females. Totally, 75.7% were relapsing remitting MS, 16.4% were primary progressive MS and 7.9% were secondary progressive MS.
      MS incidence and prevalence in Tehran has increased with a decreased female to male ratio. Despite the higher prevalence of MS amongst females, the familial recurrence was higher among males except in first degree of relatives.