The prevalence of multiple sclerosis in central Italy.

BACKGROUND: The prevalence of multiple sclerosis varies considerably throughout the world. OBJECTIVE: To better define the prevalence of MS in central Italy. METHODS: This is a population-based study conducted in the province of Frosinone, which is situated in the Lazio region, central Italy. The selected prevalence day was 1 January 2007. A total of 467 patients, with a definite diagnosis of multiple sclerosis, were considered for crude, age- and sex-specific prevalence estimation. RESULTS: The overall crude prevalence rate was 95.0 cases per 100,000 (95% confidence interval (CI) 86.6-104.0). A significantly higher prevalence rate was recorded in females (134.9, 95% CI 121.0-150.1) than in males (53.3, 95% CI 44.4-63.3) (p = 0.001). Age-specific prevalence peaked in the 25-34 year, 35-44 year and 45-54 year age groups; moreover, it was found to increase up to the 35-44 year age group in males and the 45-54 year age group in females, decreasing thereafter. The female to male ratio was 2.6. CONCLUSIONS: The results confirm that MS occurs more frequently in central Italy than might be expected on the basis of the geographic-related distribution model, thus supporting the view that this is a high-risk area for the disease.