Characterizing all-cause excess mortality patterns during COVID-19 pandemic in Mexico

Area of Science:

• Epidemiology
• Public Health
• Biostatistics

Background:

• Low COVID-19 testing rates and reporting delays in Mexico complicate accurate mortality burden assessment.
• Estimating all-cause excess deaths offers a more reliable measure of mortality impact during public health emergencies.

Purpose of the Study:

• To estimate the absolute and relative mortality impact of the COVID-19 pandemic in Mexico.
• To quantify excess mortality and compare it with confirmed COVID-19 deaths.

Main Methods:

• Utilized weekly all-cause mortality time series (2015-2020) and COVID-19 surveillance data.
• Employed Serfling regression models to estimate excess mortality rates and forecast future trends.
• Analyzed the correlation between social media (Twitter) activity about 'death' and excess mortality.

Main Results:

• Estimated 333,538 all-cause excess deaths in Mexico in 2020, a rate of 26.10 per 10,000 population.
• Males and Mexico City exhibited significantly higher excess mortality rates compared to females and other regions.
• Forecasted approximately 61,610 excess deaths in the first four weeks of 2021, with social media sentiment correlating to mortality trends.

Conclusions:

• The COVID-19 pandemic's mortality impact in Mexico is substantially underestimated by lab-confirmed COVID-19 deaths alone (38.64% of total excess deaths).
• This discrepancy suggests underreporting due to low testing or increased mortality from other causes during the pandemic.
• A model-based forecast indicated a continued high number of excess deaths in early 2021.