Population-based disease-group analysis of Spanish excess mortality in the early COVID-19 pandemic period.

Background and aim: Increased mortality during the COVID-19 pandemic is not explained exclusively by COVID-19 infection and its complications. We analysed non-COVID-19 causes of mortality in a population analysis based on data from the Spanish National Institute of Statistics.

Methods: Using monthly mortality data in Spain (January 2010-December 2020), we analysed deaths associated with cancer, blood, endocrine, mental, nervous, cardiovascular, respiratory and digestive diseases and explored the COVID-19 impact using a difference-in-difference strategy. We calculated monthly interannual variations in mortality and computed percentage change in terms of the log of deaths in month h of year t minus the log of deaths in month h in the previous year t-1.

Results: In 2020 in Spain, mortality increased 17.9% compared with 2019. COVID-19 was the leading cause of death (n=60 358), followed by ischaemic heart disease (n=29 654). Throughout 2020, monthly interannual variations in cardiovascular mortality showed an average upward trend of 1.7%, while digestive, cancer and blood diseases showed a downward trend.

Conclusions: During the COVID-19 pandemic in Spain in 2020, excess mortality was primarily related to cardiovascular mortality while mortality associated with digestive, cancer and blood diseases was reduced.