The association between acute otitis externa-related emergency department visits and extreme weather events in a temperate continental climate

Background: Climate change is a global challenge that is resulting in an increased occurrence of extreme weather events. Extreme weather events have been shown to negatively impact various health conditions, leading to an overall increase in morbidity and mortality. Ear, nose, and throat (ENT) emergencies are among the most common reasons for emergency department visits (EV). Acute otitis externa (AOE), an inflammatory external auditory canal skin infection, is the second most common condition for ENT-related emergency admissions. Previously, AOE has been associated with higher temperatures during summer; However, no data exists on extreme weather events' immediate and delayed effects on AOE-related EVs. Identifying these relationships could help predict EVs, optimize health resources, and relieve its significant burden on healthcare systems. Objective: This study aimed to associate the effects of extreme weather events with the immediate and delayed risk of AOE-related EVs.Methods: A total of 1522 AOE-related EVs from the ENT outpatient clinic of the Vienna General Hospital between 2015 and 2018 were analyzed. Meteorological data for the same study period was obtained from the Austrian Central Institution for Meteorology and Geodynamics for Vienna and a distributed lag non-linear model used to associate extreme weather events with the total number of AOE-related EVs. Relative risk (RR) and cumulative RR were analyzed over a period of 14 days.Results: AOE-related EVs showed a pronounced seasonality, with the highest occurrence in summer. The RR for AOE-related EVs was significantly increased one day after high-temperature events for seven days, to a maximum of 1.95 [1.04-3.65]. Low and high relative humidity significantly reduced the same-day occurrence of AOE-related EVs to 0.65 [0.46-0.92] and 0.74 [0.58-0.95]. Increased precipitation and wind speed significantly decreased the RR of AOE-related EVs four and seven days after occurrence. After one day, low atmospheric pressure events showed an increased RR of 1.42 [1.02-1.98] in AOE-related EVs.Conclusions: Extreme weather events significantly impact AOE-related EVs. While high mean temperatures were positively correlated with AOE-related EVs, low humidity was found to have a negative same-day effect, sup-porting the idea of multiple factors being involved in increasing the susceptibility for AOE. Knowledge of the pattern of events could allow the implementation of time-optimized prevention strategies to reduce the incidence of AOE, the frequency of EVs, and the burden on health care systems.