Excess Mortality Estimation During the COVID-19 Pandemic: Preliminary Data from Portugal

Portugal is experiencing the effects of the COVID-19 pandemic since March 2020. All-causes mortality in Portugal increased during March and April 2020 compared to previous years, but this increase is not explained by COVID-19 reported deaths. The aim of this study was to analyze and consider other criteria for estimating excessive all-cause mortality during the early COVID-19 pandemic period. Public data was used to estimate excess mortality by age and region between March 1 and April 22, proposing baselines adjusted for the lockdown period. An excess mortality of 2400 to 4000 deaths was observed. Excess mortality was associated with older age groups (over age 65) [corrected]. The data suggests a ternary explanation for early excess mortality: COVID-19, non-identified COVID-19 and decrease in access to healthcare. The estimates have implications in terms of communication of non-pharmaceutical actions, for research, and to healthcare professionals. Despite the inherent uncertainty, the excess mortality occurred between March 1 and April 22 could be 3.5- to 5-fold higher than what can be explained by the official COVID-19 deaths [corrected].