Survival and cause of death in multiple sclerosis: results from a 50-year follow-up in Western Norway.

BACKGROUND: Survival time among patients with multiple sclerosis (MS) has varied considerably according to previous reports.
OBJECTIVES: Survival and cause of death were analyzed among all patients with MS (878) with onset of MS in Hordaland County, Western Norway during 1953-2003, of whom 198 were dead at follow-up on January 1, 2005.
METHODS: Standardized mortality ratios (SMRs) and relative mortality ratios (RMRs) were calculated based on observed mortality in MS and expected mortality.
RESULTS: Median survival from onset was 41 years versus 49 years in the corresponding population, and mortality (SMR) was 2.7-fold increased in MS. The median survival was 43 years among women and 36 years among men, but women had higher relative mortality, when compared with the corresponding population, than men (RMR = 1.40). The median survival time was 45 years among young-onset patients (21-30 years) and 23 years among older-onset patients (51-60 years), but young-onset patients had higher relative mortality than older-onset patients, as shown by a significant reduction by 10-year interval of age at onset (RMR = 0.65). Median survival from onset was longer (43 years) among relapsing-remitting MS than primary progressive MS ([PPMS]; 49 years), and the relative mortality was higher in the PPMS group, (RMR = 1.55). According to death certificates, 57% died from MS.
CONCLUSION: Female patients and patients with young onset had longer median time to death but higher relative risk of dying compared with the corresponding population. PPMS had both shorter median time to death from onset and a higher relative risk of dying.