Multiple cause of death during the COVID-19 pandemic: a population study In Colombia and Brazil

Objectives To assess differences in age-standardized disease-specific mortality rates derived from the underlying cause of death (UCOD) versus multiple cause of death (MCOD) data in two Latin American countries during the COVID-19 pandemic. Methods Using all death certificates for residents of Brazil (n = 6,207,785) and Colombia (n = 1,180,880) from 2019 through 2022, we extracted UCOD and all contributing causes, assigned weights (50% to UCOD, remainder equally among contributing causes), and calculated annual age- and sex-standardized mortality rates for neoplasms, circulatory diseases, diabetes mellitus (DM), and non-COVID communicable diseases. We then computed rate differences and rate ratios contrasting MCOD with UCOD estimates. Results MCOD-DM mortality exceeded UCOD by up to 70%. In Colombia, MCOD–CVD surpassed UCOD during 2020–2021, corresponding to approximately 1,950 extra male and 1,560 extra female CVD deaths in 2021. Discrepancies for neoplasms and other communicable diseases were smaller and stable. Conclusion These findings demonstrate that MCOD methods reveal substantial underestimation of diabetes- and cardiovascular-related mortality, underscoring the value of MCOD surveillance for public health planning.