BACKGROUND: Recent studies in multiple sclerosis (MS) showed longer survival times from clinical onset than older hospital-based series. However estimated median time ranges widely, from 24 to 45 years, which makes huge difference for patients as this neurological disease mainly starts around age 20 to 40. Precise and up-to-date reference data about mortality in MS are crucial for patients and neurologists, but unavailable yet in France.
OBJECTIVES: Estimate survival in MS patients and compare mortality with that of the French general population.
METHODS: We conducted a multicenter observational study involving clinical longitudinal data from 30,413 eligible patients, linked to the national deaths register. Inclusion criteria were definite MS diagnosis and clinical onset prior to January, 1st 2009 in order to get a minimum of 1-year disease duration.
RESULTS: After removing between-center duplicates and applying inclusion criteria, the final population comprised 27,603 MS patients (F/M sex ratio 2.5, mean age at onset 33.0 years, 85.5% relapsing onset). During the follow-up period (mean 15.2 +/- 10.3 years), 1569 deaths (5.7%) were identified; half related to MS. Death rates were significantly higher in men, patients with later clinical onset, and in progressive MS. Overall excess mortality compared with the general population was moderate (Standardized Mortality Ratio 1.48, 95% confidence interval [1.41-1.55]), but increased considerably after 20 years of disease (2.20 [2.10-2.31]).
CONCLUSIONS: This study revealed a moderate decrease in life expectancy in MS patients, and showed that the risk of dying is strongly correlated to disease duration and disability, highlighting the need for early actions that can slow disability progression.
To conclude, the results of the SURVIMUS study show that there is a moderate decrease in life expectancy for MS patients, and that the risk of dying is strongly correlated with disease duration, and probably disability progression, highlighting the need for actions that can delay disability progression. Even though excess mortality starts only after 20 years of disease duration, interventions such as DMTs or multidisciplinary care should be started as soon as possible in the disease course in order to maximize their efficacy in slowing down disability progression,
Kaplan-Meier estimates revealed that 89.6% [88.9-90.2] and 72.3% [70.4-74.1] of MS patients were still alive 25 and 40 years after clinical onset respectively.