Prevalence of multiple sclerosis in the L'Aquila district, central Italy

Abstract

Objective-To estimate the prevalence of multiple sclerosis in the L'Aquila district, central Italy. Methods - All available case sources were screened. Definite and probable cases of multiple sclerosis, classified according to the Poser criteria, were considered as prevalent cases. Results - On the prevalence day, 31 December 1996, 158 patients (105 women and 53 men; ratio 2:1) affected by definite (n = 131) or probable (n = 27) multiple sclerosis were alive and resident in the L'Aquila district. Mean (SD) age was 38.4 (11.9) years (38.9 (11.7) years for women and 38.5 (12.3) years for men, p = 0.9). The overall crude prevalence was 53.0/100,000 (95% confidence interval (95% CI) = 45.4-62.0); 68.4/100,000 (95% CI = 56.5-82.8) in women, and 36.7/100,000 (95% CI = 28.1-48.0) in men. The prevalence was similar (55.9/100,000) when standardised to the 1996 European population. Mean (SD) age at onset of multiple sclerosis was 29.4 (9.6) years and mean (SD) duration of the disease was 9.4 (7.4) years, without any significant difference between sexes. Mean age at onset was significantly higher in patients with the primary progressive than in those with the relapsing-remitting course (p = 0.0002, Scheffe's test). Conclusions - The prevalence found in the L'Aquila district gives support to the consideration of Italy as an area in which multiple sclerosis has been shown to have high prevalence at least in the populations that were surveyed recently.