Epidemiology and disease burden of tuberous sclerosis complex in France: A population‐based study based on national health insurance data

OBJECTIVE: Tuberous sclerosis complex (TSC) is a rare multisystem disorder, often associated with epilepsy. This retrospective study aimed to identify patients with TSC, including those with epilepsy, from a French healthcare claims database, and to report incidence, prevalence, and healthcare costs and resource utilization. METHODS: The anonymized French health insurance database (SNDS) covers almost the entire French population. Patients with TSC were identified as having ≥1 International Classification of Diseases, Tenth Revision (ICD‐10) diagnosis code Q85.1 or a long‐term disease (LTD) registration over the inclusion period (2006–2017). Patients with an ICD‐10 epilepsy code or who were dispensed ≥1 antiseizure medication (ASM) in the same year or after their TSC diagnosis were identified as having TSC with epilepsy. Newly diagnosed patients over the inclusion period constituted the incident cohort. Healthcare costs (patients with recorded costs only), healthcare resource use, and ASM dispensation are reported for patients with 2018 data. RESULTS: In 2018, 3139 prevalent patients with TSC were identified (crude prevalence, 4.69 per 100 000); the incident cohort comprised 2988 patients (crude incidence, 0.44 per 100 000). Among patients with TSC, 67% (2101/3139) had epilepsy (mean [standard deviation, SD] age: 28.8 [18.8] years; male: 48%). Among patients with epilepsy, total mean (SD) annual healthcare costs were €11 413 (27 620) per capita (outpatient, 63%; inpatient, 37%), 46% were hospitalized during 2018 (mean [SD]: 1.8 [10.9] acute care visits per patient), and 65% visited a hospital specialist. Among patients with epilepsy, medication (mean [SD]: €4518 [12 102] per capita) was the greatest contributor (63%) to outpatient costs, and in 2018, 74% were dispensed ≥1 different ASM and 9% were dispensed ≥4 ASMs. SIGNIFICANCE: TSC with epilepsy was associated with substantial healthcare costs and resource utilization, particularly outpatient and medication costs. Many patients with TSC with epilepsy were prescribed multiple ASMs, suggesting refractory epilepsy.