Epidemiology of the COVID-19 pneumonia in a group of hospitals from Madrid -Spain during the full period of the State of Alarm- HM cohort.

Abstract

Introduction: To describe the epidemiology pattern of the COVID-19 pandemic during all Spanish State of Alarm.

Methods: Retrospective, observational, cohort and multicenter study. Inclusion criteria: age ≥18 years, admitted for COVID-19 pneumonia in any HM Hospitals Group center. Exclusion criteria: voluntary discharge, death in the emergency department, transfer outside HM or incomplete data.

Results: During the study period, 2,992 patients were admitted for COVID-19 pneumonia, of whom 295 died (9.86%). Survivors vs. non-survivors: differences in age and comorbidities, but a similar interaction network. 197 (6.48%) required ICU admission, with 52 (26.39%) deaths. Incidence for variants: original 4.05 cases/day, alpha 3.82, delta 1.16, omicron 1.35.

Conclusions: Almost 1 in 10 patients with COVID-19 pneumonia died, a proportion that rose to 1 in 4 in the ICU. Unexpectedly, the comorbidity network was similar between survivors and non-survivors. Different variants were associated with varying hospital admission rates but did not alter the "peaks and troughs" pattern of the pandemic.