Journal Article

Changes in Healthcare Utilization After the 2022 Seoul Metropolitan Flood: Applying a Generalized Synthetic Control Approach

Yun, Yeseul, Jang, Hoyeon, Kim, Jaiyong, Benmarhnia, Tarik, Han, Changwoo, Jang, Marnpyung, Yoon, Jaeyoung

2024

Overview

Floods can have adverse health effects and impose a burden on healthcare systems. However, the potential consequences of floods on specific medical causes in densely populated metropolitan cities has not been characterized yet. Therefore, we evaluate the changes in healthcare utilization patterns after the 2022 Seoul flood using nationwide health insurance data. Based on the flood inundation map, districts within the flooded municipalities of Seoul were classified as severe‐(n = 12), mild‐(n = 22), or non‐(n = 38) flood‐affected districts. Capitalizing on the timing of the flood as a natural experiment, a generalized synthetic control method was applied to estimate changes in the number of disease‐specific hospital visits in flood‐affected districts during 2 weeks after the flood. We found excess hospital visits for external injuries (20.2 visits, 95% CI: −6.0, 45.2) and fewer visits for pregnancy and puerperium (−3.0 visits, 95% CI: −5.1, −0.5) in residents of flooded districts. When comparing severe‐ and non‐flood districts, the increase in hospital visits for external injuries (56.2 visits, 95% CI: 17.2, 93.2) and a decrease in hospital visits related to pregnancy and puerperium (−5.3 visits, 95% CI: −8.4, −1.6) were prominent in residents living in severe‐flood affected districts. Disease specific analysis showed an increase in hospital visits for injuries to the elbow and forearm, ankle and foot injuries, and chronic lower respiratory diseases in severe‐flood‐affected districts. However, these impacts were not observed when comparing the mild‐ and non‐flood‐affected districts. Our study suggests an immediate and substantial change in medical demand following flood exposure, highlighting the importance of public health responses after flood events. Plain Language Summary This study evaluated the acute medical demands after a 2022 Seoul Metropolitan City flooding event, highlighting the need for preparedness and response to future flood disasters. We observed an increase in hospital visits related to external injuries and chronic lower respiratory infection and a decrease in pregnancy and puerperium related hospital visits in residents of severely flood‐affected districts. However, such changes were not observed in residents of mildly flood‐affected districts. Future healthcare management plans following flood should include adjustments to changes in the demand for medical services during and after flood events. Key Points We evaluated the changes in healthcare utilization patterns after 2022 Seoul flood The universal health insurance data and a generalized synthetic control were used There was an increase in injuries and a decrease in pregnancy related hospital visits after flood

• Publisher: John Wiley & Sons, Inc,Wiley,John Wiley and Sons Inc,American Geophysical Union (AGU)
• Subject: Debris Flow and Landslides / Dermatitis / Drought / external injury / Extreme Events / Fatalities / flood / Floods / Geohealth / Health care / health effect / Health Impact / Health risks / Health services utilization / hospital use / Hospitals / Hydrological / Hydrology / Impacts of Climate Change: Human Health / Infections / Informatics / Injuries / Life Sciences / Mathematical Geophysics / National health insurance / Natural Hazards / Nonlinear Geophysics / Oceanography: General / Persistence, Memory, Correlations, Clustering / Population density / Pregnancy / Probability Distributions, Heavy and Fat‐tailed / Public Health / Research methodology / Respiratory diseases / Santé publique et épidémiologie / Scaling: Spatial and Temporal / Space Plasma Physics / Stochastic Phenomena / Stochastic Processes / synthetic control / Temporal Analysis and Representation / Time Series Analysis / Time Series Experiments / Waterborne diseases