MCOD methods reveal substantial underestimation of diabetes- and cardiovascular-related mortality compared to underlying cause of death data, with MCOD-DM mortality exceeding UCOD by up to 70% in Brazil and Colombia during the COVID-19 pandemic.
Multiple cause of death (MCOD) analysis revealed that diabetes mellitus mortality was underestimated by up to 70% when using only underlying cause of death (UCOD) data.
In Colombia, MCOD-derived cardiovascular disease (CVD) mortality surpassed UCOD estimates during 2020–2021, corresponding to approximately 1,950 extra male and 1,560 extra female CVD deaths in 2021.
Discrepancies between MCOD and UCOD estimates for neoplasms and non-COVID communicable diseases were smaller and stable across the study period.
The study used a weighted MCOD methodology assigning 50% weight to the underlying cause of death and distributing the remaining 50% equally among contributing causes.
MCOD surveillance methods reveal substantial underestimation of diabetes- and cardiovascular-related mortality, underscoring the value of MCOD surveillance for public health planning.
This research suggests that official death statistics, which typically record only a single 'underlying cause' of death, may significantly undercount deaths related to diabetes and heart disease, particularly during the COVID-19 pandemic. By analyzing over 6 million death certificates from Brazil and over 1 million from Colombia between 2019 and 2022, the researchers compared the standard approach (counting only the primary cause of death) with a more comprehensive approach that also considers all contributing causes listed on the death certificate. They found that diabetes-related deaths were undercounted by as much as 70%, and cardiovascular disease deaths in Colombia were also substantially undercounted during 2020 and 2021, amounting to roughly 3,500 additional CVD deaths in 2021 alone that the standard method missed. The study found that these gaps were much smaller and more stable for cancer deaths and deaths from other infectious diseases, suggesting that COVID-19 specifically made it harder to accurately attribute deaths involving diabetes and heart disease using the standard single-cause approach. When someone with diabetes or heart disease dies with COVID-19, the pandemic disease may be listed as the primary cause, making the chronic disease invisible in standard statistics. This research suggests that public health agencies and policymakers should consider adopting multiple-cause-of-death analysis as a routine surveillance tool, especially during health emergencies like pandemics. Undercounting deaths from chronic diseases like diabetes and cardiovascular disease can lead to misallocation of healthcare resources and incomplete understanding of how pandemics affect people with pre-existing conditions in Latin America and potentially other regions.
Durán D, Carabali M, Bilal U, Nicolau B, Kaufman J. (2026). Multiple cause of death during the COVID-19 pandemic: a population study In Colombia and Brazil.. International journal of public health. https://doi.org/10.3389/ijph.2026.1609429