An ecological study of industry in a high-risk region of multiple sclerosis

18-year temporal trend of multiple sclerosis in southern Iran

BACKGROUND

Multiple Sclerosis (MS) imposes significant burdens on patients, their families, and national healthcare systems particularly when there is a resource constraint. Proper prioritization and resource allocation are therefore essential for any effective disease management. Accordingly, we sought to assess the temporal profile of MS incidence over the past two decades in southeast Iran.

METHODS

A longitudinal design was employed using data from the Iranian multiple sclerosis registry system from March 2001 to March 2019 (n=6034). Annual age-standardized incidence rates of MS (cases of clinically isolated syndrome were also included) were calculated and the trend of incidence from 2001 to 2018 was analyzed.

RESULTS

The age-adjusted incidence rate of MS raised from 1.72/100,000 in 2001 to 11.29/100,000 in 2018 (average of 18-year incidence rate was 6.30/100,000), indicating a notable rise in the incidence of MS (P-Value<0.001). However, the female to male ratio of 3.62 remained relatively stable during the study period.

CONCLUSION

Our study suggests that, in Fars province, the incidence of MS has been remarkably rising over the past two decades. We recommend further studies to better understand the determinants of this pattern. Implementing effective policies in lowering the burden of MS is another important step in this regard.

Prevalence and Incidence of Multiple Sclerosis in Fars Province, Southern Iran

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory and demyelinating disease of the central nervous system, which is accompanied by significant disabilities. Although there are some published data regarding the epidemiological features of MS in other parts of Iran, scarce data are available about the prevalence and demographic characteristics of MS in Fars province. The current study aimed to address the prevalence and incidence rate of MS as well as the temporal trend of the disease in Fars province, southern Iran.

METHODS

This historical retrospective cohort study was carried out in Fars Multiple Sclerosis Society affiliated with Shiraz University of Medical Sciences. All the consecutive patients who fulfilled 2010 McDonald criteria for definite MS were included in the study. The patients' gender, age at time of diagnosis, education, and clinical course were recorded. The prevalence and incidence rates were also calculated.

RESULTS

This study was conducted on 3,354 patients. Among the patients, 2,689 (80.2%) were female and 665 (19.8%) were male. The female/male ratio was 4.04. The point prevalence rate of the disease was 72.1/100,000 persons in October 2013. This index was 116.5 per 100,000 persons in females (95% CI: 113.4-119.6) and 28.3 per 100,000 persons in males (95% CI: 26.8-29.9). The mean annual incidence rate was 5.2/100,000 from 2002 until 2012.

CONCLUSION

Considering Kurtzke classification, Fars is a high-risk area for MS and women are affected more compared with men. Moreover, the incidence rate sharply increased in the last decade.