Objectives:
To assess patient- and hospital-level predictors of death and variation in death rates following admission for COVID-19 in England’s first two waves after accounting for random variation. To quantify the correlation between hospitals’ first and second wave death rates.

Design:
Observational study using administrative data.

Setting:
Acute non-specialist hospitals in England.

Participants:
All patients admitted with a primary diagnosis of COVID-19.

Primary and secondary outcomes:
In-hospital death.

Results:
Hospital Episode Statistics (HES) data were extracted for all acute hospitals in England for COVID-19 admissions for March 2020 to March 2021. In wave one (March-July 2020) there were 74,484 admissions and 21,883 deaths (crude rate 29.4%); in wave two (August 2020 to March 2021) there were 165,642 admissions and 36,040 deaths (21.8%). Wave two patients were younger, with more hypertension and obesity but lower rates of other comorbidities. Mortality improved for all ages; in wave two it peaked in December 2020 at 24.2% (lower than wave one’s peak) but halved by March 2021. In multiple multilevel modelling combining HES with hospital-level data from Situational Reports, wave two and wave one variables significantly associated with death were mostly the same. The median odds ratio for wave one was just 1.05 and for wave two was 1.07. At 99.8% control limits, 3% of hospitals were high and 7% were low funnel plot outliers in wave one; these figures were 9% and 12% for wave two. Four hospitals were (low) outliers in both waves. The correlation between hospitals’ adjusted mortality rates between waves was 0.45 (p<0.0001). Length of stay was similar in each wave.

Conclusions:
England’s first two COVID-19 waves were similar regarding predictors and moderate inter-hospital variation. Despite the challenges, variation in death rates and length of stay between hospitals was modest and might be accounted for by unobserved patient factors.