Long‐term epidemiology of multiple sclerosis in the Northern Seville District

OBJECTIVES Comprehensive epidemiologic data for multiple sclerosis (MS) in Spain are limited. The aim of this study was to collect epidemiologic data on MS in the Northern Seville District of Spain. MATERIALS AND METHODS This longitudinal study identified possible MS cases every year from nine centres between 1 January 1991 and 31 December 2011. Patients with a confirmed diagnosis of MS were included. MS data prior to enrolment were collected retrospectively from clinical records and prospectively during quarterly follow-up clinic visits. Variables included age at onset, age at diagnosis, treatment, follow-up duration, number of visits, number of relapses, change in the number of relapses over time and Expanded Disability Status Scale score. The incidence and prevalence of MS rate were calculated. RESULTS Overall, 156 patients with MS were identified (111 females; mean follow-up 7.5 years). Most patients had relapsing-remitting MS (73.7%); primary progressive disease was less frequent than secondary disease (10.9% vs 15.4%). The yearly incidence of MS was 4.6 per 100,000, and the prevalence at 31 December 2011 was 90.2 per 100,000. CONCLUSIONS The annual MS incidence rate in this southern region of Spain was higher than previously reported rates in Spanish studies.