EVOLVING CHARACTERISTICS OF COVID-19 INPATIENTS AT AN AUSTRALIAN CENTRE

Intro: Since the declaration of the global pandemic in March 2020, the novel coronavirus disease (COVID-19) has caused dynamic pressures on healthcare systems worldwide. This study aims to compare the demographic and clinical characteristics, management, and outcomes of patients with COVID-19 at a single centre in Sydney, Australia. Methods: Using the clinical coding data, we identified all patients aged > 16 years admitted to our centre between February 1st, 2020, and March 31st, 2022. We categorised the time periods ‘pre-delta’ (February 1st, 2020 – June 15th, 2021), ‘delta’ (June 16th, 2021 – November 25th, 2021), and ‘omicron’ (November 26th, 2021 – March 31st, 2022). We retrospectively extracted the demographic, administrative, and clinical data from the electronic medical records and performed a descriptive analysis of the data. Findings: A total of 1842 patients were identified (pre-delta N=18; delta N=788; omicron N=1036). The percentage of male patients was 83%, 54%, and 56% and the median ages at admission were 55, 49, and 70 years during the pre-delta, delta, and omicron periods, respectively. The median length of hospital stay was the longest during the pre-delta period (8.5 days vs. 7 vs. 6). ICU admission rate was 39%, 21%, and 10% for each period and of the ICU-admitted patients 43%, 40%, and 36% respectively required mechanical ventilation. Inhospital mortality was the highest during the omicron period (pre-delta inhospital mortality 5.6%; delta 4.1%; omicron 7.3%). A total of 219 (28%) patients of delta and 185 (18%) of omicron periods received at least one dose of dexamethasone and 175 (22%) and 44 (4.2%) respectively received at least one dose of remdesivir. Conclusion: The demographic and clinical characteristics of admitted COVID-19 patients varied across the ‘pre-delta’, ‘delta’, and ‘omicron’ time periods. The median age at admission and in-hospital mortality was the highest during the omicron period.