Understanding the role of pandemic preparedness during the COVID-19 crisis is challenging considering substantial cross-country gaps in data sources, heterogeneity in reporting of COVID-19 outcomes and differences in population age structures and healthcare delivery systems. ...this may be the most well-specified model considering that the residuals are substantially closer to being constant (studentised Breusch-Pagan (BPT=6.91; p=0.075)). Table 1 Country-level effect sizes of 2021 Global Health Security measures on comparative excess mortality ratio Coefficient (95% CI) P value Global Health Security Score −0.17 (−0.32 to −0.03) 0.0168*  Prevention score −0.07 (−0.17 to 0.03) 0.1580  Detection score −0.09 (−0.16 to −0.02) 0.0187*  Response score −0.11 (−0.27 to 0.04) 0.1612  Health system score −0.06 (−0.18 to 0.06) 0.3086  International norms score −0.13 (−0.26 to −0.01) 0.0407*  Risk environment score −0.25 (−0.40 to −0.10) 0.0014* Effect sizes compare a 5-score difference in each index. ...taking into account age likely already adjusts for a substantial proportion of country-level income considering the very strong correlation between log income and fraction of population 65 years and greater in 2019 (Pearson’s r=0.74).