Mortality by Cause of Death in Brazil: A Research Note on the Effects of the COVID-19 Pandemic and Contribution to Changes in Life Expectancy at Birth

Abstract

We analyze and quantify the ways the COVID-19 pandemic affected other causes of death in Brazil in 2020 and 2021. We decompose age-standardized mortality rate time series for 2010-2021 into three additive components: trend, seasonal, and remainder. Given the long-term trend and historical seasonal variation, we assume that most of the impact of the COVID-19 pandemic will be left in the remainder. We use a regression model to test this assumption. We decompose the contributions of COVID-19 deaths (direct effect) and those of other causes (indirect effects) to the annual change in life expectancy at birth (e0) from 2017 to 2021. The COVID-19 pandemic not only increased rates for other causes of death but also decreased rates for some causes. Broadly, the remainders mirror the COVID-19 pandemic waves. The direct effects of the pandemic reduced e0 by 1.88 years in 2019-2020 and by 1.77 in 2020-2021. Indirect effects increased e0 by 0.44 in 2019-2020 and had virtually no effect on e0 in 2020-2021. Whether the trajectories of mortality rates and annual gains in e0 will return to prepandemic levels and their interregional gradients depend on whether a nonnegligible number of patients who recovered from COVID-19 will suffer premature mortality.

Keywords: COVID-19 mortality; Indirect effects of COVID-19 mortality; Life expectancy at birth; Life expectancy decomposition; Time-series decomposition.