Prescription trends for combined oral contraceptives and thromboembolism incidence in Japan before and after public awareness events in 2013-2015.

ObjectiveCombined oral contraceptives (COCs) for dysmenorrhea management have been covered by the Japanese universal health insurance system since 2008. Several public awareness events regarding COC prescriptions for dysmenorrhea were implemented between 2013 and 2015, including media reports on COC-related fatalities in 2013, drug safety alerts in 2014, and new clinical guidelines in 2015. This study aimed to examine the trends in patient characteristics, coagulation testing, and thromboembolism incidence before and after these events.MethodsWe used the JMDC claims database to identify patients with dysmenorrhea prescribed COCs between 2009 and 2021. We evaluated the annual trends in guideline-listed thromboembolism risk factors (age ≥ 40 years, obesity, and smoking), frequency of patients undergoing coagulation testing among patients prescribed COCs, and thromboembolism incidence.ResultsOf 860 840 patients with dysmenorrhea, 173 502 received COCs. The proportion of patients prescribed COCs decreased temporarily from 12.2% to 11.2% in 2014. The proportion of new COC prescriptions increased for women aged <40 years and decreased for those aged ≥40 years. The proportions of patients with obesity and smokers remained stable from 2016. The frequency of coagulation testing increased annually, rising sharply from 15% to 22% in 2014. The incidence of thromboembolism with treatment decreased from 11.8 to 9.9 per 10 000 person-years from 2016 to 2021.ConclusionAlthough no direct causal relationship is clear, public health awareness events might have influenced clinical practices, including the preferential selection of lower-risk patients and promotion of coagulation screening, possibly resulting in a decline in the incidence of thromboembolism.