D1.284 - Trends in Recurrent Anaphylaxis Triggered by Food, Drug, and Insect Allergies from 2015 to 2021: A Population-Based Retrospective Cohort Study Using the National Insurance Claims Database of Japan

Anaphylaxis is the most severe and life-threatening allergic reaction and is most commonly triggered by food, drugs, and insect stings. According to the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB), a unique and comprehensive database of health insurance claims, we previously reported that the number of patients who received adrenaline (Ad) increased 1.48 times from 2015 to 2021. A better understanding of related information is essential for preventing and managing recurrent anaphylaxis. This study evaluated trends in recurrent anaphylaxis triggered by food, drug, and insect allergies in Japan.

We conducted a population-based retrospective cohort study using an NDB dataset. We extracted from the original NDB database for all patients who were prescribed Ad for food, drug, and insect allergies across all age groups from April 2015 to March 2021 from the NDB dataset. In this study, we analyzed the number of patients who were re-administered Ad within two years of initial administration and examined trends over time.

The number of patients re-administered Ad was 395 in 2015, 362 in 2016, 315 in 2017, 366 in 2018, 302 in 2019, 222 in 2020, and 128 in 2021, respectively. The percentage of males ranged from 47.3% to 57.0%, and the percentage of patients aged 0–19 years (children) ranged from 43.6% to 58.1%. The rate of decline in the number of patients changed significantly after 2020 (44% in 2020 and 68% in 2021). In 2021, the rate of decline was more significant for children than patients aged 20–99 years (adults), and was 77% for children compared to 66% for adults. The highest rate of decline was for food allergies (73%), and there was also a decline in insect allergies (41%). However, drug allergies, which showed a decreasing trend before 2019, began increasing in 2020 and 2021 (125% in 2020 and 150% in 2021).

This study showed that some patients were re-administered Ad every year within two years of initial administration. Ongoing monitoring is needed to assess whether anaphylaxis management is improving, as the decline in cases after 2020 may be influenced by changes in living conditions due to the COVID-19 pandemic.