Recording of multiple sclerosis in the Swiss cause of death statistics. A 10-years mortality follow-up of the Berne prevalence study

Based on data from a multiple sclerosis (MS) prevalence study which had bee n carried out in 1986 in the canton of Berne, Switzerland a followup was pe rformed 10 years later to gather information on mortality in the original s tudy population. The authors used information on residency and death as gat hered from municipal offices and, additionally, by record-linkage with the Swiss cause of death statistics. Slightly more than 80% of the cases were i dentified unequivocally as of January 1996. Among them, 21% of the cases di ed during the ten-year period; 70% of them have an MS entry in the cause of death statistics, mostly as the main cause of death. A large proportion of the non-identifiable cases appear to be related to mortality; thus, the fi ndings here do not provide a promising basis for certain further analyses. In conclusion, continuous updating of personal data is the only way to avoi d loss to follow-up in the carefully assembled prevalence database.