Increased risk of death in COVID-19 hospital admissions during the second wave as compared to the first epidemic wave: a prospective, single-centre cohort study in London, UK

Abstract

Background The second coronavirus disease (COVID-19) epidemic wave in the UK progressed aggressively and was characterised by the emergence and circulation of variant of concern alpha (VOC 202012/01). The impact of this variant on in-hospital COVID-19-specific mortality has not been widely studied. We aimed to compare mortality, clinical characteristics, and management of COVID-19 patients across epidemic waves to better understand the progression of the epidemic at a hospital level and support resource planning. Methods We conducted an analytical, dynamic cohort study in a large hospital in South London. We included all adults (≥ 18 years) with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) who required hospital admission to COVID-19-specific wards between January 2020 and March 2021 (n = 2701). Outcome was COVID-19-specific in-hospital mortality ascertained through Medical Certificate Cause of Death. Results In the second wave, the number of COVID-19 admissions doubled, and the crude mortality rate dropped 25% (1.66 versus 2.23 per 100 person-days in second and first wave, respectively). After accounting for age, sex, dexamethasone, oxygen requirements, symptoms at admission and Charlson Comorbidity Index, mortality hazard ratio associated with COVID-19 admissions was 1.62 (95% CI 1.26, 2.08) times higher in the second wave. Conclusions Although crude mortality rates dropped during the second wave, the multivariable analysis suggests a higher underlying risk of death for COVID-19 admissions in the second wave. These findings are ecologically correlated with an increased circulation of SARS-CoV-2 variant of concern 202012/1 (alpha). Availability of improved management, particularly dexamethasone, was important in reducing risk of death.

Omicron variant (B.1.1.529) of SARS-CoV-2: understanding mutations in the genome, S-glycoprotein, and antibody-binding regions

“…For example, increased infection with the Delta variant (B.1.617.2) in India resulted in a serious second wave that killed large numbers of people [12]. Similarly, the emergence of the Alpha variant initiated a second wave in the UK [13]. The emergence of the variant has created new concerns related to the pandemic.…”

Critical policies disparity of the first and second waves of COVID-19 in the United Kingdom

“…As a result, the UK imposed its first nationwide lockdown on March 23. Subsequently, the number of daily new cases and daily deaths gradually decreased, the cumulative deaths curve flattened, the transmission and hospitalization rate also decreased [ 12 ]. The percentage of people testing positive for COVID-19 rose slightly in July after a low in June, and then held steady for some time.…”

Demographic and clinical characteristics and outcomes of COVID-19 patients admitted to a university hospital in the west of Iran: a retrospective study in the third wave

“…Rapid emergence of new SARS-CoV-2 variants due to viral mutations increases its ability to escape the immune system and infect more patients, renders immunization ineffective, and affects the effectiveness of public health measures ( 5 ). In September 2020, Alpha became the dominant variant in Iran ( 6 ), which was associated with double the risk of hospitalization during 14 days of a positive molecular test in the UK and Scotland compared to previous variants ( 7 ). However, this variant predominated in Iran before starting vaccination, which made it one of the worst COVID-19 peaks so that the daily death toll exceeded 700.…”