School contact between patients with multiple sclerosis.
We have investigated whether there was more school contact among patients with multiple sclerosis (MS) than expected by chance, suggesting that a transmissible infection occurring at school age might be an aetiologic factor. A case-control-within-a-cohort study was conducted using the 1930-1950 birth cohort. Of 198 000 persons 92 had developed MS in the period 1943-1975 and 3 matched controls for each case were selected. The number of links between all possible pairs of cases was estimated, as well as the number of cases involved in contact with at least one other case. Three measures of school contact were included in the analysis. No evidence of increased school contact among MS cases relative to controls was found.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D003718:Denmark; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000453:epidemiology*; D013334:Students