Deaths "due to" COVID-19 and deaths "with" COVID-19 during the Omicron variant surge, among hospitalized patients in seven tertiary-care hospitals, Athens, Greece.

In Greek hospitals, all deaths with a positive SARS-CoV-2 test are counted as COVID-19 deaths. Our aim was to investigate whether COVID-19 was the primary cause of death, a contributing cause of death or not-related to death amongst patients who died in hospitals during the Omicron surge and were registered as COVID-19 deaths. Additionally, we aimed to analyze the factors associated with the classification of these deaths. We retrospectively re-viewed all in-hospital deaths, that were reported as COVID-19 deaths, in 7 hospitals, serving Athens, Greece, from January 1, 2022, until August 31, 2022. We retrieved clinical and laboratory data from patient records. Each death reported as COVID-19 death was characterized as: (A) death "due to" COVID-19, or (B) death "with" COVID-19. We reviewed 530 in-hospital deaths, classified as COVID-19 deaths (52.4% males; mean age 81.7 ± 11.1 years). We categorized 290 (54.7%) deaths as attributable or related to COVID-19 and in 240 (45.3%) deaths unrelated to COVID-19 In multivariable analysis The two groups differed significantly in age (83.6 ± 9.8 vs. 79.9 ± 11.8, p = 0.016), immunosuppression history (11% vs. 18.8%, p = 0.027), history of liver disease (1.4% vs. 8.4%, p = 0.047) and the presence of COVID-19 symptoms (p < 0.001). Hospital stay was greater in persons dying from non-COVID-19 related causes. Among 530 in-hospital deaths, registered as COVID-19 deaths, in seven hospitals in Athens during the Omicron wave, 240 (45.28%) were reassessed as not directly attributable to COVID-19. Accuracy in defining the cause of death during the COVID-19 pandemic is of paramount importance for surveillance and intervention purposes.