Clinical characteristics and outcomes of elderly COVID-19 patients admitted to ICU during Chinese Mainland’s Omicron Wave: A multicenter retrospective cohort study

Background: There is limited information on elderly patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant infections. We aimed to describe the characteristics and outcomes of elderly patients with Omicron variant infections admitted to the intensive care unit (ICU) on the Chinese Mainland and to evaluate the risk factors associated with mortality in these patients. Methods: We conducted a multicenter retrospective study including elderly patients with SARS-CoV-2 infection who were admitted to the ICU from November 1, 2022, to February 11, 2023, on the Chinese Mainland. The primary objective of the study was to describe the characteristics and outcomes of elderly ICU patients with Omicron variant infections. The secondary objective was to evaluate the risk factors for mortality of these patients. Results: We included 1605 patients aged 65 years or older diagnosed with severe or critical COVID-19 and admitted to ICUs in 59 hospitals across different areas of the Chinese Mainland. The median age was 78 years (IQR 72–84), with male patients accounting for 1164/1605 (72.5%), and 1459/1605 (90.9%) of patients having at least one comorbidity. The median APACHE II scores and SOFA scores were 16 (IQR 11–23) and 5 (IQR 3–8), respectively. Among these patients, 553 (34.5%) were recovery discharged, 557 (34.7%) died in the ICUs, and 495 (30.8%) discharged voluntarily during therapy and were later confirmed dead after discharge. Multivariable logistics analysis indicated that older age, coinfection, high levels of white blood cell count, blood urea nitrogen, D-Dimer, and lactate at admission were against for recovery discharged. Conclusions: Elderly patients infected with the Omicron variant of SARS-CoV-2 and admitted to the ICU had a considerable mortality rate. Better understanding of risk factors for mortality may improve clinical management and more rational allocation of limited medical resources during a COVID-19 surge.