Excess mortality during the COVID-19 pandemic and its spatial distribution in the state of Pernambuco, Brazil: an ecological study

Exceso de mortalidad durante la pandemia de covid-19 y su distribución espacial en el estado de Pernambuco, Brasil: un estudio ecológico

Objective  To investigate excess mortality during the COVID-19 pandemic and its spatial distribution in Pernambuco, Brazil.

Methods  This was an ecological, descriptive and analytical study of deaths, by municipality, recorded on the Mortality Information System, in 2020 and 2021. Excess mortality was measured by comparing observed and expected deaths, the latter estimated by calculating standardized mortality ratio (SMR). SMR and respective confidence intervals (95%CI) were calculated. Spatial analysis was performed by calculating the Global and Local Moran Index.

Results  Excess mortality was 20.6% and 27.5%, respectively, in 2020 and 2021, with positive spatial correlation (p-value < 0.05). More populous municipalities (2020: SMR = 1.26; 95%CI 1.24;1.27 and 2021: SMR = 1.34; 95%CI 1.32;1.34), more developed municipalities (2020: SMR = 1.43; 95%CI 1.41;1.44 and 2021: SMR = 1.51;95%CI 1.50;1.53) and municipalities in the Sertão region (2020:SMR = 1.31;95%CI 1.30;1.33 and 2021: SMR = 1.44; 95%CI 1.42;1.46) showed greater excess deaths.

Conclusion  Excess mortality coincided with peak periods of COVID-19 transmission.

Keywords
Excess Mortality; COVID-19; Spatial Analysis; Proportional Mortality Ratio; Ecological Studies

Main results  There was excess mortality in Pernambuco in 2020 and 2021, which coincided with the peak of the COVID-19 epidemic curve. Municipalities with higher population density, developed municipalities and municipalities in the Sertão region had higher excess deaths.

Implications for services  The results highlighted the effects of the pandemic on mortality in the state. Strengthening mortality surveillance can assist health management in formulating strategies and public policies for the Brazilian National Health System.

Perspectives  Adoption of this type of analysis could contribute to identification of inequalities in the mortality burden between different population groups, and could be used for analysis of future health challenges.