Geographic variations of multiple sclerosis in Iran: A population based study

Background: The epidemiology of Multiple sclerosis (MS) has changed in recent decades. Considering that the incidence and geographical variations of MS is not well known in Iran. The present study was conducted to investigate the incidence of MS and its geographic variations in Iran. Methods: Data from a national registry, coordinated by the Ministry of Health (MOH), were collected for this study. In Iran, all MS patients are eligible to receive care and treatment services based on their records in this registry. Therefore, it seems that the related data are comprehensive with very high coverage, particularly in recent years. In this study, the annual incidence rates were calculated based on year of diagnosis of MS. Results: In this registry, 32,633 new cases were recorded between 2011 and 2016. After standardized for age, the mean annual incidence rate was 6.5 per 100,000 populations. It was 10.2 and 2.9 in women and men respectively. This incidence ranged from 1.7 to 12.8 in provincial level, with a higher intensity in the central part of the country. Conclusion: It seems that the incidence rate of MS and its ratio in females and males are more or less comparable with the dominant patterns in developed countries, although its variation within the country is very considerable.