Impact of a high-profile sudden cardiac death on emergency department utilization: a multi-campus interrupted time...

High-profile public health events can be temporally associated with significant shifts in healthcare-seeking behavior. We aimed to quantify the surge in emergency department (ED) volume and characterize the demographic shifts following a high-profile sudden cardiac death (SCD) event of a nationally prominent public figure.

A retrospective study was conducted across two major hospital cohorts (N = 15,981). We employed interrupted time series (ITS) analysis to estimate the immediate level shift in daily ED visits. An XGBoost model with SHAP (SHapley Additive exPlanations) interpretability was developed as an exploratory phenotyping tool to characterize the surge based on clinical and behavioral features. Findings were confirmed using an internal validation cohort.

Following the SCD event, daily ED volume exhibited a significant immediate level shift (Main: +24.4%; Internal Validation: +34.7%,p < 0.001). A subtle but robust demographic shift toward younger populations was observed (Median age decrease: 2.2 years,p < 0.001). Machine learning identified Age, Nighttime Presentation, and Cardiovascular Department attendance as the features most strongly associated with the surge phenotype. Notably, the SHAP dependence analysis revealed a sharp, non-linear escalation in surge probability for individuals aged < 45 years, particularly during nocturnal hours. Despite the volume surge, no significant increase in mortality or acute myocardial infarction diagnoses was observed, indicating that the surge was predominantly associated with low-risk individuals exhibiting reassurance-seeking behavior.

Media-driven events can be followed by a structured, large-scale surge in emergency department utilization, predominantly among younger, low-risk individuals seeking reassurance. These demographic and behavioral findings are consistent with the cyberchondria phenomenon, which may produce a dilution of clinical severity without increasing hard endpoints, potentially straining acute care resources. Targeted public health communication and adaptive triage strategies are essential to preserve emergency capacity during periods of heightened media-associated health concerns.