Speaker
Description
Background
Excess mortality captures the comprehensive burden of COVID-19, yet cross-national disparities remain poorly understood. We examined the impact of economic development and national preparedness on mortality outcomes across 59 countries from 2020 to 2024.
Methods
Countries were stratified by IMF economic classifications. We evaluated the association between the 2021 Global Health Security (GHS) Index and excess mortality using multivariable regression and explainable machine learning (SHAP).
Findings
Emerging market economies experienced significantly higher total and non-COVID excess mortality during 2020–2021. While higher GHS scores correlated with lower mortality in pooled analyses, this association attenuated upon stratification, suggesting an aggregation bias driven by structural heterogeneity. Early detection and the national risk environment were the primary drivers of resilience. Crucially, these factors operated on a functional threshold basis rather than through linear, incremental improvements.
Conclusions
Pandemic mortality follows structural capacity gradients rather than transient policy variations. Preparedness indices should be interpreted as markers of broad structural capacity. Strengthening global resilience requires prioritizing foundational surveillance and institutional robustness to achieve functional readiness over uniform indicator improvements.
