Incidence of multiple sclerosis in Iran: a nationwide, population-based study

• Published in: Public health (London) Vol. 175; pp. 138 - 144
• Main Authors: Hosseinzadeh, A., Baneshi, M.R., Sedighi, B., Kermanchi, J., Haghdoost, A.A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01-10-2019; Elsevier Science Ltd
• Subjects: Adolescent; Adult; Autoimmune diseases; Confidence intervals; Correlation analysis; Developed countries; Diagnosis; Female; Females; Health risks; High risk; Humans; Incidence; Incidence trend; Iran; Iran - epidemiology; Longitudinal Studies; Male; Males; Medical diagnosis; Middle Aged; Multiple sclerosis; Multiple Sclerosis - epidemiology; Population studies; Population-based studies; Registries; Young Adult; Iran; Multiple sclerosis; Incidence trend; Iran; Autoimmune diseases
• DOI: 10.1016/j.puhe.2019.07.013
• EISSN: 1476-5616
• ISSN: 0033-3506

The incidence of multiple sclerosis (MS) is not well known in Iran. This study was conducted to estimate the trends in annual MS incidence in Iran from March 21, 2010, to March 20, 2016.
Longitudinal study.
In this longitudinal study, data for all MS patients fulfilling McDonald criteria were obtained from a national registry, coordinated by the Ministry of Health (MOH). In Iran, all MS patients are eligible to receive public care and treatment services based on their records in this registry, and thus nearly all MS patients are registered in this database. The annual incidence rates were calculated based on year of diagnosis and were standardized using the World Health Organization (2000–2025) population as a standard.
In this registry, 36,287 (8202 [22.6%] males and 28,085 [77.4%] females) confirmed MS cases were registered by the MOH between 2010 and 2016. The female-to-male ratio was 3.11. The mean age of patients was 31.6 ± 0.9 years at the time of diagnosis. It was 31.3 ± 0.8 and 32.3 ± 0.9 for females and males, respectively. Overall incidence rate was 6.7/100,000 population (95% confidence interval [CI]: 6.2–7.2); 10.5 and 3.0 in females and males, respectively. The age-adjusted incidence rates increased significantly from 4.4 (95% CI: 4.3–4.6) in 2010 to 5.8 (95% CI: 5.7–6.0) in 2016, with its peak at 6.5 (95% CI: 6.3–6.6) in 2014.
This study revealed that Iran is a high-risk area for MS disease and that MS incidence and female-to-male ratio are more or less comparable with the dominant patterns in developed countries. Also, this study showed that the incidence trend of MS in Iran is similar to regional and global observed patterns.
•This study was designed to estimate the incidence of multiple sclerosis (MS) across the whole population of Iran.•The MS incidence increased over the 7 years (2010-2016) of the study.•The average annual incidence was estimated at 6.7/100,000, comprising 10.5 and 3.0 in females and males respectively.•Our results show that the incidence of MS in Iran is higher than its geographical position had previously suggested.