The Impact of the Third Wave of the COVID-19 Pandemic on the Elderly and Very Elderly Population in a Tertiary Care Hospital in Portugal

Background: COVID-19 poses a significantly more serious threat to adults aged 65 and above, with a higher mortality rate. This study aims to describe the outcome of COVID-19 patients in the elderly and very elderly population admitted to a tertiary care Portuguese hospital. The authors defined the elderly population (65 to 79 years) and the very elderly population (≥ 80 years). Methods: We conducted a retrospective observational single center study in the internal medicine ward of a tertiary hospital from November 1, 2020 to January 31, 2021. All COVID-19 patients aged over 65 years were enrolled. Results: Of the 824 patients with SARS-CoV-2 infection, 586 (71%) were aged above 65 years. Of them, 61.7% were very elderly and 32.9% were elderly. The hospital recorded 53 (27.5%) deaths in the elderly group and 182 (46.3%) in the over-80 group. In the elderly population, only 32 patients had critical illness compared to the 79 in the very elderly group. In addition to respiratory complications, acute kidney failure and liver dysfunction were noted. In both groups, mortality was higher when there was acute kidney injury (AKI). With respect to treatment, dexamethasone and azithromycin did not show a statistically significant difference between the groups. The need for oxygen therapy over 4L/min, high-flow therapy, and mechanical invasive ventilation was related to higher mortality in both groups. Conclusion: The very elderly group had a higher number of deaths compared to the elderly group due to multiple comorbidities. Respiratory failure was the most frequently occurring complication. Surprisingly, dexamethasone and azithromycin therapy did not show a statistically significant effect in both age groups despite their current widespread usage in COVID-19 treatment worldwide.