The Emergence of COVID-19 as a Cause of Death in 2020 and its Effect on Mortality by Diseases of the Respiratory System in Spain: Trends and Their Determinants Compared to 2019

OBJECTIVE: To analyze the causes of death by diseases of the respiratory system in Spain in 2020, with special interest in COVID-19; also its trends and determinants, and compare them with 2019. MATERIAL AND METHODS: Retrospective cohort study. The coding of all those causes of death by diseases of the respiratory system were regrouped. A descriptive analysis of all deaths and by gender, age, and the 17 Autonomous Communities (CC.AA.) was performed. Also, odds ratios of death in crude and multivariate analysis by logistic regression were estimated. RESULTS: In Spain in 2020, 60,358 deaths were attributed to “COVID-19 virus identified” and another 14,481 to “COVID-19 virus not identified (suspicious)”. Regrouping the specific causes of death, in 2020 the diseases of the respiratory system caused a total of 139,880 deaths, which corresponds to 28.3% of all deaths in Spain. Compared to 2019, an increase of 68.5% was observed. By gender, deaths by diseases of the respiratory system were higher in men (32.0%) than in women (24.6%), although in specific causes the percentage was higher in women with suspected COVID-19, asthma, respiratory insufficiency and other diseases of the respiratory system. Finally, the variables associated with death from COVID-19 in the multivariate analysis were being male, increasing age (maximum at 80 years), completed studies up to secondary level, employed, and single or widowed marital status, although with a marked variation by CC.AA. CONCLUSIONS: In Spain in 2020, COVID-19 produced a large increase (68.5%) in deaths by diseases of the respiratory system compared to the previous year.