Prevalence of paediatric-onset multiple sclerosis in France, disease management and use of disease-modifying therapies in this specific population
Résumé
Background: Onset of multiple sclerosis (MS) before 18 years old, called Paediatric-onset MS (PoMS), is considered as a rare disease, with prevalence estimates ranging from 0 to 3 cases per 10,000 inhabitants in the world. In France, about 100,000 people live with MS, but it is not currently known how many children and youth are affected. Regarding disease management, most of the disease-modifying therapies (DMTs) licensed in the adult-MS population is not approved in the PoMS population and they are frequently used off-label.
Objective: The present study aims to estimate the prevalence of PoMS in France and describe characteristics of the disease management, especially DMTs prescriptions, of this specific population, using administrative health data over the period 2010 to 2015.
Methods: Access to the national health insurance database which covers 97% of the French population offers the opportunity to perform a population-based nationwide study on that topic. PoMS cases were identified over 2010-2015 in patients < = 18 years thanks to a 3-criteria algorithm using diagnoses of hospital admissions, MS-specific DMTs and MS long disease duration status. Access to health services and use of DMTs over the 6-year study period was described.
Results: Overall, 1104 cases (742 girls and 382 boys) were identified, leading to an estimated prevalence of approximately 1 case per 10,000 inhabitants. Age at MS identification was < 6 years in 1.4%, 6-11 years in 6.8%, 11-16 years in 32.6% and >=16 years in 59.2%. Regarding DMTs, 39.5% never received any DMT over 6 years. In treated patients, mean age at first DMT initiation was 16 years old and the three most frequently prescribed drugs were interferons, glatiramer acetate and natalizumab. Moreover, about 89% of cases had at least one hospital admission, whatever the cause. Finally, five deaths occurred over the study period (4 other causes than MS, 1 unknown).
Conclusion: Data issued from the national health insurance system offers the opportunity to estimate the prevalence of PoMS in France and to study care practices in this specific population at national level, without selection bias. Therapeutic sequences will be deeply studied, as well as the profiles of health care providers involved in the follow-up of such children.