Prevalence, sociodemographic characteristics and spatial distribution of systemic lupus erythematosus in France: a nationwide study using health claims data with insights into hydroxychloroquine prescription patterns.

Abstract

Objective: Our primary objective was to estimate an updated prevalence of SLE in France in 2020. We also explore the sociodemographic characteristics of patients with SLE, the social and spatial variability and also study and use hydroxychloroquine prescription patterns as an external validation for case ascertainment.

Methods: We used the French national health data system, which covers almost all of the 67 million people living in France. Prevalent cases were identified among inpatients and people granted a long-term disease status, using the International Classification of Diseases, 10th Revision code for SLE. Filled prescriptions of hydroxychloroquine were also counted.

Results: In 2020, we identified 54 804 patients with SLE; this corresponds to an overall prevalence of 81.6 per 100 000 people. The prevalence estimates were 137.0 per 100 000 in women and 22.5 per 100 000 in men. The highest standardised prevalences were observed in the French overseas departments and in the mainland departments to which people from these departments frequently migrate. Unexpectedly, we did not find an association between the prevalence of SLE in mainland France and a social deprivation index. A prescription of hydroxychloroquine was filled at least once for 67.7% of the patients overall and reached 86.7% of those aged between 20 and 24.

Conclusions: Our study provides recent, accurate estimates of the prevalence and social and geographical distribution of SLE in France. We observed an almost twofold increase in prevalence, relative to a previous estimate (from 2010) based on the same database. The high proportion of patients receiving a prescription of hydroxychloroquine is in line with current treatment guidelines.