Prevalence of multiple sclerosis in Sardinia: A systematic cross-sectional multi-source survey

Partial surveys in sub-regions of Sardinia have suggested a high prevalence of multiple sclerosis (MS) on the island, relative to other Mediterranean populations. We assessed the island-wide prevalence of MS and its detailed distribution in Sardinia.

The study population consisted of 5677 MS patients, 1735 men and 3942 women, living in Sardinia. Neurologists retrospectively examined electronic and paper-based records of patients with a diagnosis of MS. The data were then linked to the administrative health information systems. Crude, age-, and sex-specific prevalence estimates of disease were calculated.

The overall age-adjusted MS prevalence was 330 per 100,000 (95% confidence interval (CI) 321-338) in individuals older than 15 years, 447 in women (95% CI 433-461), and 205 in men (95% CI 195-214). The prevalence was highest in the Ogliastra and Nuoro districts, respectively, 425 (95% CI 372-478) and 419 (95% CI 387-451), and lowest in the Olbia-Tempio district, 217 (95% CI 195-239). Most cases had relapsing-remitting MS (79.3%), 16.3% had secondary-progressive MS, and 4.4% had primary-progressive MS.

These prevalence are among the highest reported so far worldwide. They provide estimates for comparative analyses in other populations and are essential for public health interventions.