Factors associated with COVID-19 related hospitalisation, critical care admission and mortality using linked primary and secondary care data

Cummings, L.; Ebyarimpa, I.; Cheetham, N.; Tzortziou Brown, V.; Brennan, K.; Panovska-Griffiths, J.

Background To protect vulnerable groups from COVID-19 infection it is important to better understand the risk factors associated with COVID-19 morbidity and mortality. In this study, we identified factors that increase the risk of hospitalisation, intensive care unit (ICU) admission and mortality in inner North East London (NEL)- a diverse area that experienced some of the highest COVID-19 mortality rates, during the first COVID-19 wave, in the UK. Methods We used multivariate logistic regression analysis on a linked primary and secondary care data from people aged 16 or older (registered with a GP practice in inner NEL) with confirmed COVID-19 infection between 1 February 2020 and 30 June 2020. We determined odds ratios (OR), 95% confidence intervals (CI) and p-values for the association between demographic, deprivation and clinical factors with COVID-19 hospitalisation, ICU admission and mortality. Findings Over the study period 1,781 people were diagnosed with COVID-19, of whom 1,195 (67%) were hospitalised, 152 (9%) admitted to ICU and 400 (23%) died. Results confirm previously identified risk factors: being male, or of Black or Asian ethnicity, or aged over 50. Obesity, type 2 diabetes and chronic kidney disease (CKD) increased the risk of hospitalisation while obesity increased the risk of being admitted to ICU and underlying CKD, stroke and dementia increased the risk of death. Importantly, we identified that having learning disabilities was strongly associated with increased risk of death (OR=4.75, 95%CI=(1.91,11.84), p=0.001). Additionally, having three or four co-morbidities increased the risk of hospitalisation (OR=2.34,95%CI=(1.55,3.54),p<0.001 and OR=2.40, 95%CI=(1.55,3.73), p<0.001 respec-tively) and death (OR=2.61, 95%CI=(1.59,4.28), p<0.001 and OR=4.07, 95% CI= (2.48,6.69), p<0.001 respectively). Interpretation Our findings confirm that age, sex, ethnicity, obesity, CKD and diabetes are important determinants of risk of COVID-19 hospitalisation or death. For the first time, we also identify additional patient cohorts that need to be actively protected in the current and subsequent COVID-19 waves, including people with learning disabilities and multi-morbidity.