Cause-specific hospitalization risk and cost attributable to tropical cyclones in South Korea

Background: Tropical cyclones (TCs) are one of the most destructive climate disasters, which can cause injuries and mortality due to strong winds and flooding. In addition to the direct impact, TCs can also indirectly induce adverse health outcomes such as infectious diseases, mental disorders, and deterioration of chronic diseases resulting from contaminated food and water, property loss, or poor accessibility to healthcare. However, the research on the disease outbreaks attributable to TCs and related socioeconomic burden is limited. We aimed to investigate the risk and medical cost of cause-specific hospitalization associated with TC exposures.

Methods: This study used the Korea National Health Information Database from June to October between 2010 and 2023, which is a nationwide claim-based database on healthcare utilization for the entire population of South Korea. In order to focus on the short-term impact of TCs, we only considered hospital admissions via the emergency department (ED admissions). TC days were defined as the days with the TC-related maximum wind speeds ≥17.5 m/s, which were calculated using a TC track data and a wind field model. To estimate the association between TC and cause-specific ED admission, we applied a case time series design by conducting a fixed-effects model with a quasi-Poisson family and a distributed lag linear model for each disease category. The association with TC exposures was specified using a distributed lag linear model considering lag impact of seven days.

Results: The average number of TC days per decade among the entire 250 districts was 5.3 times, ranging from 1.4 to 18.6 times. TC exposures were associated with increased risk of ED admissions due to mental disorders, neurological diseases, endocrine diseases, and cardiovascular diseases, with relative risks (95% confidence intervals [CI]) of 1.22 (1.00–1.49), 1.19 (0.99–1.24), 1.11 (0.99–1.24), and 1.08 (1.00–1.17), respectively. Medical cost of ED admissions attributable to TCs was highest for cardiovascular diseases (2349.5 million KRW, 95% empirical CI: 51.2–4475.4 million KRW), followed by neurological diseases and endocrine diseases.

Conclusions: This nationwide study provides evidence that TCs can have an impact on the outbreaks of some diseases and impose a substantial medical cost burden in South Korea. Our findings suggest that the health impacts of TCs extend beyond immediate injuries, underscoring the importance of incorporating various diseases management into TC preparedness and response strategies to mitigate the growing health and economic burdens associated with TCs.