Characteristics and Outcomes in Hospitalized Adult Patients Infected with the SARS-CoV-2 Omicron Variant at a Large Healthcare System in South Florida, January 1 -14, 2022

ABSTRACT

Background. The SARS-CoV-2 Omicron variant has been rapidly spreading worldwide. We aimed to characterize Omicron severity by assessing in-hospital deaths and intensive care admissions in a large healthcare system in South Florida during an Omicron predominant surge. Methods. Laboratory-confirmed COVID-19 adult patients hospitalized during January 1 -14, 2022 were retrospectively reviewed. Risks of in-hospital mortality and intensive care admission were estimated using logistic regression models. Analyses were stratified by age >= 65 years and vaccination status, and further adjusted for sex, comorbidities, and history of a previous COVID-19 infection. Results. 500 consecutively hospitalized COVID-19 Omicron patients were included. The median age was 69 (IQR, 53-80) years, and 271 (54.2%) were women. The most common comorbidities were hypertension (65.5%), diabetes (32%), and chronic kidney disease (24%). 260 (52%) patients were fully vaccinated (defined as a patient who received 2-dose vaccines), and 32 (6.4%) were previously infected with COVID-19. 252 (50.4%) patients required supplemental oxygen, 54 (10.8%) required intensive care unit (ICU) admission, and 44 (8.8%) patients required mechanical ventilation. At study closeout of March 7, 2022, case fatality rates among patients aged 18 -29 years, 30 -39 years, 40-49 years, 50-59 years, 60-69 years, 70-79 years, and >= 80 years were 0%, 2.2%, 6.4%, 5.3%, 8.0%, 5.7%, and 15.4% respectively ( p < 0.001), with the median time from hospital admission to death being 13 days (IQR, 6.5-20.5) (Figure 1). Patients aged >= 65 years had 2.6 times higher rates for in-hospital mortality (OR, 2.63;95% CI, 1.29-5.33;p =0.007) than those aged < 65 years, but were comparable for ICU admission (OR, 0.85;95% CI, 0.49-1.52;p =0.586). Past vaccination offered no protection against in-hospital mortality (OR, 1.18;95% CI, 0.64-2.19;p =0.599) or ICU admission (OR, 1.16;95% CI, 0.66-2.06;p =0.6) (Figure 2). In multivariable-adjusted models, patients aged >= 65 years had a higher in-hospital mortality than those aged < 65 years (Figure 2). Conclusion. This case series provides characteristics and outcomes of hospitalized adult patients with COVID-19 Omicron variant. Past COVID-19 vaccination did not impact ICU admission rate nor in-hospital mortality.