Mortality by cause of death in Brazil: effects of the COVID-19 pandemic and contribution to changes in life expectancy at birth

We investigate the consequences of the COVID-19 pandemic on other underlying causes of death in Brazil in 2020 and 2021. We estimate monthly age-standardized mortality rates for 2010-2021 and decompose those time series into three additive components: trend, seasonality, and remainder. Given the long-term trend and historical seasonal fluctuations, we assume that any impact from the pandemic will be left on the remainder. We also decompose the contributions of COVID-19 deaths (direct effect) and those from other causes (indirect effects) to the annual change in life expectancy at birth (𝑒) from 2017 to 2021. Broadly, the remainder mirrors the trajectory of pandemic waves. The impact of the COVID-19 pandemic on other causes of death was not limited to increases but also decreases. The direct effects of the pandemic reduced 𝑒 by 1.89 years between 2019 and 2020 and 1.77 between 2020 and 2021. Indirect effects increased 𝑒 by 0.44 between 2019 and 2020 and had virtually no impact on 𝑒 between 2020 and 2021. Whether trajectories in mortality rates and annual gains in 𝑒 will quickly return to pre-pandemic levels depends on governmental actions to mitigate the consequences of the COVID-19 pandemic. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil (CAPES) - Finance Code 001 - which funds the Demography Program at the Federal University of Minas Gerais (UFMG). FF acknowledges support from the Brazil Office of the David Rockefeller Center for Latin American Studies, Harvard University. CMT acknowledges support from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes We use death registers from the Mortality Information System (SIM) of the Brazilian Ministry of Health and population data from the Brazilian Institute for Geography and Statistics (IBGE), both publicly available.