Prescription trends in anti-seizure medications for adult patients with epilepsy in Japan: A retrospective cohort study using the database of health insurance claims between 2015 and 2019

Objective: To investigate whether newer anti-seizure medications (ASMs) are widely prescribed for a range of adult patients in Japan, including patients with previously and newly diagnosed epilepsy, or with focal and generalized epilepsies. Methods: A retrospective cohort study was conducted using the Japanese insurance claims database including 8.4 million people to identify adults (>= 16 years of age) with epilepsy diagnosis code identified between January 2015 and December 2018. Patients were included in the prevalent population if epi-lepsy was already diagnosed at baseline, and in the incident population if prior baseline data for at least 12 months included no epilepsy diagnosis code or ASM prescription. Patients were followed up from the month when the initial oral ASM was prescribed for up to 4 years until the end of 2019 as long as at least one ASM was prescribed. Proportions of prescribed oral ASMs were analyzed by population with epilepsy (prevalent vs. incident) and classification (focal vs. generalized). Anti-seizure medications were classified into older vs. newer ASMs according to the date of approval before and after 1990, respectively. Results: A total of 24,691 patients fulfilled the eligibility criteria for the analysis. Of these, 21,046 and 3,645 were included in the prevalent and incident populations, respectively. The proportion of older ASMs significantly decreased, whereas the proportion of newer ASMs significantly increased (p < 0.0001) during the study period. This trend was more apparent in the population with incident epi-lepsy than in that with prevalent epilepsy, and was also apparent in the subgroup of focal epilepsy, but not in that of generalized epilepsy. Levetiracetam was the most frequently prescribed of the newer ASMs. Conclusion: Newer ASMs became more widely prescribed throughout the study period in populations with both prevalent and incident epilepsies, as well as the subpopulation with focal epilepsy. The advan-tages of newer ASMs such as better safety profiles may have led to the increasing proportions of prescrip-tions and newer ASMs may increase the treatment options for patients. (c) 2022 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).