Wave comparisons of clinical characteristics and outcomes of COVID-19 admissions - Exploring the impact of treatment and strain dynamics

Abstract

Objectives: Dexamethasone has now been incorporated into the standard of care for COVID-19 hospital patients. However, larger intensive care unit studies have failed to show discernible improvements in mortality in the recent wave. We aimed to investigate the impacts of these factors on disease outcomes in a UK hospital study.

Methods: This retrospective observational study reports patient characteristics, interventions and outcomes in COVID-19 patients from a UK teaching hospital; cohort 1, pre 16th June-2020 (pre-dexamethasone); cohort 2, 17th June to 30th November-2020 (post-dexamethasone, pre-VOC 202,012/01 as dominant strain); cohort 3, 1st December-2020 to 3rd March-2021 (during establishment of VOC202012/01 as the dominant strain).

Results: Dexamethasone treatment was more common in cohorts 2 and 3 (42.7% and 51.6%) compared with cohort 1 (2.5%). After adjusting for risk, odds of death within 28 days were 2-fold lower in cohort 2 vs 1 (OR:0.47,[0.27,0.79],p = 0.006). Mortality was higher cohort 3 vs 2 (20% vs 14%); but not significantly different to cohort 1 (OR: 0.86,[0.64, 1.15],p = 0.308).

Conclusions: The real world finding of lower mortality following dexamethasone supports the published trial evidence and highlights ongoing need for research with introduction of new treatments and ongoing concern over new COVID-19 variants.

Keywords: COVID-19 variants; COVID-19 waves; Dexamethasone.

Fig. 1

Changes in prevalence of new COVID-19 variant, SE England. Estimates from the ONS (11) suggest that the prevalence of the novel COVID-19 variant (VOC202012/01) within the community in South East England started to become dominant from December 2020 onward.

Fig. 2

(A) 28-day mortality according to first risk score and cohort. Curves represent predicted probability of death within 28 days of first positive test according to cohort based on a binomial logistic regression model fitted to observed data. Shaded areas indicate 95% confidence interval. (B) Risk-adjusted mortality according to cohort. Odds of death within 28 days of first positive test based on a logistic regression model including first risk score and cohort.