[Case-fatality rates of SARS-CoV-2 infection according to Autonomous Communities during the second epidemic wave in...

In Spain, health systems are transferred to the Autonomous Communities (AC), constituting 19 health systems with differentiated management and resources. During the first epidemic wave of COVID-19, differences were observed in reporting systems and in case-fatality rates (FR) between the AC. The objective of this study was to analyze the FR according to AC. during the 2 nd epidemic wave (from July 20 to December 25, 2020), and its relationship with the prevalence of infection.

A descriptive observational study was carried out, extracting the information available on the number of deaths from COVID-19 registered in the Ministry of Health, the Health Councils and the Public Health Departments of the AC, and according to the excess mortality reported by the System Monitoring of Daily Mortality (MoMo). The prevalence of infection was estimated from the differences between the second and fourth rounds of the ENE-COVID study and their 95% confidence intervals. The global FR (deaths per thousand infected) were calculated according to sex, age groups (< 65 and ≥ 65 years) and AC. The age-Standardized Fatality Rates (SFR) of the AC were calculated using the FR of Spain for each age group. These estimates were made with officially declared deaths (FRo) and excess deaths estimated by MoMo (FRMo). The correlations between the prevalences of infection and the FRo and FRMo were estimated, weighting by population.

For the whole of Spain, the FRo during the second epidemic wave was 7.6%, oscillating between 3.8% in the Balearic Islands and 16.4% in Asturias, and the TLMo was 10.1%, oscillating between 4.8% from Madrid and 21.7% in Asturias. Significant differences were observed between the FRo and the FRMo in the Canary Islands, Castilla la Mancha, Extremadura, the Valencian Community, Andalusia and the Autonomous Cities of Ceuta and Melilla. The FRo was significantly higher in men (8.2%) than in women (7.1%). The FRo and FRMo were significantly higher in the age group ≥ 65 years (55.4% and 72.2% respectively) than in the group <65 years (0.5% and 1.4% respectively). The Basque Country, Aragon, Andalusia and Castilla la Mancha presented SFR significantly higher than the global FR of Spain. The correlations between the prevalence of infection and the FRo were inverse.

The case-fatality from COVID-19 during the second epidemic wave in Spain improved compared to the first wave. The case-fatality rates were higher in men and the elderly people, and varied significantly between AC. It is necessary to delve into the analysis of the causes of these differences.