Multiple sclerosis (MS), a demyelinating autoimmune disorder of the central nervous system, is estimated to affect 2.8 million individuals worldwide [1], particularly women. It is often diagnosed between the age of 25 and 35 years [2]. MS has no known cure and leads to progressive cognitive, neurological and physical impairment over the lifetime [3]. As MS reduces life expectancy only marginally, patients with MS (PwMS) live with the disease for many decades and this is associated with increasing and complex healthcare needs [4], [5]. The prevalence of MS is influenced by many factors, and shows wide geographical variations, even within the same country, meaning that some regions will have a higher disease burden, with different healthcare needs [6], [7].

The third edition of the Atlas of MS by the MS International Federation reported an increase in MS prevalence by 35% in Europe and by 16% in the world between 2013 and 2020 [1]. As the last prevalence estimate for France (151.2 PwMS/100,000; n = 99,123) is from 2012 [8], it needs to be updated to identify potential changes and trends and also to inform key decision-makers about the range and scope of the healthcare needs of PwMS.

Since 2009, France has integrated multiple databases from hospitals (private and public), in- and out-patient care clinics, and data on prescribed drug reimbursements into the French national health insurance database [Système national des données en santé (SNDS)]. This database covers approximately 66 million inhabitants (i.e. ∼99% of the French population) and has been increasingly used for epidemiological studies [9]. The SNDS database was also used for estimating MS prevalence in France in 2012 [8].

The main objective of this study was to estimate MS prevalence in France on December 31, 2021 and to describe the French MS population in terms of age, sex and geographical location using the SNDS database.