Survey of pharyngeal foreign bodies in Japan: An ecological study using the nationwide claims data.

ABSTRACT

OBJECTIVE: Pharyngeal foreign bodies (PFBs) are a prevalent disease affected by food culture and dietary habits, with fish bones as the leading cause. Most studies were limited to specific regions, and a nationwide survey was not conducted in Japan. In this ecological study, we aimed to conduct a nationwide analysis of outpatient PFB cases in Japan over three years, focusing on seasonal trends, sex- and age-stratified cases, and regional differences. METHODS: We used the National Database of Health Insurance Claims and Specific Health Checkups of Japan open data from April 2019 to March 2022. The case data were analyzed by month, age, sex, and prefecture. Additionally, we calculated the standardized claim ratios (SCRs) for each prefecture and investigated the association between dietary habits, food culture, and SCR of PFBs using a two-level linear regression model. RESULTS: We analyzed a total of 164,337 outpatient PFB cases in Japan, revealing an average incidence rate of 45.6 per 100,000 persons. The seasonal trend revealed a peak in July each year from 2019 to 2021, confirming seasonality in PFB incidents. Children reported a higher incidence rate. Living west of Japan and expenditure on fish and shellfish had a strongly positive association with the SCR of PFBs. CONCLUSION: Our nationwide survey reveals that, even within Japan, there were regional variations influenced by food culture and dietary habits. The data showed that PFB incidence was higher among children, highlighting the need for preventive education. LEVEL OF EVIDENCE Level 3.