all patients registered in 17 selected French OFSEP centres with core dataset with a sufficient level of data
Diagnosis a of definite or probably MS according to Poser or McDonald criteria. With an MS onset date between January 1st, 1960 and December 31st, 2015.
With a postal residence address well informed in the OFSEP database.
You may not be if
MS patients with less than one year's disease duration by the study end will be excluded.
