Epidemiological study of multiple sclerosis in the Illawarra region

Multiple sclerosis (MS) is an autoimmune inflammatory demyelinating disease that causes significant disabilities. Latest MS epidemiological data in Australia reveal rising prevalence. No epidemiological study of MS has been conducted so far in the Illawarra region.

To calculate prevalence and incidence of MS in the Illawarra region and compare with data from other regions, states and the national prevalence.

Data of MS patients in the Illawarra region were collected from hospital medical records, ambulatory care units and hospital pharmacy. Prevalence was calculated for alive MS patients on 30 June 2018 expressed per 100 000 population. Yearly adjusted incidence rate was calculated for 10 years (2009-2019), expressed as cases per 100 000 population-years.

Estimated MS prevalence in the Illawarra region was 116.6 per 100 000 population with yearly incidence (2009-2019) of 5.06 cases per 100 000 population-years (female to male, 3:1). Relapsing-remitting MS (RRMS) was the most common type (277/397; 69.7%) with primary progressive MS (PPMS) in 52/397 (13%), and secondary progressive MS (SPMS) in 45/397 (11.3%; unknown in 23). The commonest age at diagnosis ranged between 30 and 39 years for all types with RRMS and PPMS between 30-39 years and 40-49 years respectively. The most common recorded treatment was natalizumab (103 patients), followed by fingolimod (82 patients) and interferon (58 patients).

The calculated MS prevalence in the Illawarra region is higher than New South Wales and the Australian average MS prevalence. Further epidemiological studies focussing on MS risk factors and other factors bearing on MS prevalence in the Illawarra region are required.