Incidence of Multiple Sclerosis in the City of Catania: A 50-Year Observational Population-Based Study.

INTRODUCTION: The incidence of multiple sclerosis (MS) has shown varying temporal trends across European countries in recent decades, particularly in high-incidence areas. We aimed to describe the incidence risks and temporal trends of MS in the city of Catania over the last five decades (1970-2019). METHODS: Incident cases of MS resident in the city of Catania at disease onset were identified using the registries of the main MS centers. The annualized incidence risk was based on the year of clinical onset. RESULTS: From 1970 to 2019, a total of 754 incident cases were identified. The annualized incidence risk increased sharply from 0.7/100,000 in 1970-1974 to 9.2/100,000 in 2015-2019. Female-to-male ratio increased from 0.83 (95% CI: 0.26-2.62) in 1970-1974 to 2.14 (95% CI: 1.47-3.17) in 2015-2019. The mean age at onset was 29.1 ± 8.2 years in 1970-1974, reaching a mean of 37.1 ± 11.3 years in 2015-2019. CONCLUSIONS: Incidence of MS has been steadily increasing in the city of Catania, reaching a peak in 2015-2019 confirming Catania as one of the highest-incidence areas in Italy. Additionally, we observed an increasing age at onset for both sexes, which may be attributable to improved diagnosis of late-onset MS cases.