Introduction: To date, epidemiological studies on multiple sclerosis in Spain have been basically prevalence studies, and the data on incidence recorded have been the result of different methodologies, with no definition of the criteria for inclusion.
Objective: To carry out a study of incidence with prospective collection/review of cases over a prolonged period of time.
Patients and methods: Over 12 years, between 1 March 1986 and 31 December 1997, we collected data prospectively for patients with a definite diagnosis of multiple sclerosis. The year of incidence was considered to be when the patient fulfilled clinical criteria for diagnosis of the disease.
Results: On 31 December 1997 in the Alcoi Health District there were 54 patients with clinically defined multiple sclerosis (a prevalence of 41.28 cases per 100,000 inhabitants). Of these, 45 patients were diagnosed during the period studied, with an average incidence of 2.82 cases per 100,000 inhabitants per year. Only 15 patients were confirmed before 1986.
Conclusions: This is the most prolonged study of the incidence of multiple sclerosis carried out in Spain. The figures found for incidence are in contrast to those found in previous years for prevalence and incidence. Analysis of the data suggests that the incidence of multiple sclerosis in the Alcoi district has changed and has increased since the second half of the 1980s.