#6004 THE EFFECT OF COVID-19 WITH OR WITHOUT ACUTE KIDNEY INJURY ON INPATIENT MORTALITY IN ENGLAND

Abstract

Abstract Background and Aims COVID-19 and acute kidney injury (AKI) are each associated with increased mortality but the interaction between these two conditions has not been adequately investigated with appropriate control groups. The aim of this national study was to assess patient characteristics and mortality and well as associations with higher mortality in patients with or without COVID and with or without AKI. Method We extracted 3,324,748 finished consultant episodes (FCE) of all adult patients admitted patients between March 20 and March 21 from England's national database of all hospitals. We excluded patients on chronic dialysis, acute dialysis in CKD, acute dialysis with no AKI codes or not residing in England. We also excluded multiple FCEs within same spell and duplicate FCEs. We extracted all diagnoses and procedure codes for the cohort. We divided the study period in two phases of SARS CoV-2 strains. “Other” strain of SAR CoV-2 was dominant between 1st March 2020 and 21st December 2020 and “Alfa” strain was dominant between 22nd December 2020 to 17th May 2021. The end date of each phase was based on more than 50% decline in each variant. We further categorised phases based on publication of the RECOVERY trial. Results There were 663,628 patients with 2,385,337 admissions out which 856,544 had AKI as identified by N17 codes while 1,528,793 had no AKI. There were 1,008,774 admissions in 133,988 patients who did not have AKI or COVID (group 1) and 520,019 admissions in 256,037 patients who had COVID (group 2). Amongst admission with AKI, there were 630,342 admissions in 218,270 patients who did not have COVID-19 (group 3) and 226,202 admissions with COVID in 55,333 patients (group 4). Patients in group 4 were older (75.4 ± 13.8 years) and had greater length of stay (17.1 ± 17 days) than all other groups. Acute dialysis was performed in 1.4% of patients in group 3 and 3.6% of patients in group 4. Crude in-hospital mortality was highest in group 4 at 28.7% and lowest in group 1 (1.1%). Critical care requirement was lowest in group 1 (1.2%) compared to group 4 (10.9%) as was ITU mortality (4.8% versus 47.8%). In multivariable analysis, when compared with group 1, patients in group 4 had highest odds of death (OR 22.28, 95%CI 21.79, 22.78) followed by patients with group 2 (OR 9.67, 95%CI 9.46, 9.88) (Figure 1). Patients in group 3 had OR of 6.44, 95%CI 6.30, 6.58. Odds of death were lower during post-RECOVERY phase with “Other” (OR 0.80, 95%CI 0.79, 0.81) and "Alfa" (OR 0.86, 95%CI 0.85, 0.87) SARS CoV-2 strains (Figure 2). Conclusion This national study shows that the COVID pandemic had great impact on mortality in England and the odds of death increased substantially when complicated by AKI. Moreover, AKI associated with COVID was associated with a substantially higher odds of death than AKI due to other causes. The change in practice after publication of the RECOVERY trial was associated with a lower odds of death.