Clinical Characteristics and Predictors of Mortality in Patients with COVID-19 Infection Outside Intensive Care

Abstract

Background/introduction: The coronavirus disease 2019 (COVID-19) pandemic has affected all aspects of inpatient hospital medicine with patients admitted from level 1 (general medical wards) to level 3 (intensive care). Often, there are subtle physiological differences in these cohorts of patients. In particular, in intensive care, patients tend to be younger and have increased disease severity. Data, to date, has combined outcomes from medical and intensive care cohorts, or looked exclusively at intensive care. We looked solely at the level 1 (medical) cohort to identify their clinical characteristics and predictors of outcome.

Patients and methods: This was a retrospective study of adult patients admitted to a central London teaching hospital with a diagnosis of COVID-19 from 23rd March to 7th April 2020 identified from the hospital electronic database. Any patients who required level 2 or 3 care were excluded.

Results: A total of 229 patients were included for analysis. Increased age and frailty scores were associated with increased 30-day mortality. Reduced renal function and elevated troponin blood levels are also associated with poor outcome. Baseline observations showed that increased oxygen requirement was predictive for mortality. A trend of increased mortality with lower diastolic blood pressure was noted. Lymphopenia was not shown to be related to mortality.

Conclusion: Urea and creatinine are the best predictors of mortality in the level 1 cohort. Unlike previous intensive care data, lymphopenia is not predictive of mortality. We suggest that these factors be considered when prognosticating and for resource allocation for the treatment and escalation of care for patients with COVID-19 infection.

Keywords: COVID-19; ICU; frailty; lymphopenia; mortality; renal dysfunction.

Figure 1

Patient Cohort Characteristics. (A–L) Patient cohort comparisons Home (n=154) compared with Death (n=75) for Frailty Score, Fraction of Inspired Oxygen (FiO2), Oxygen Saturations (SpO2), Urea, Creatinine, Estimated Glomerular Filtration Rate (eGFR), Troponin T, D-Dimer, Neutrophil count, Lymphocyte count, Monocyte count and C Reactive Protein (CRP). Displayed as Median, IQ range and maximum and minimum. Comparisons between groups were performed using the Wilcoxon rank sum tests for continuous variables and the chi-squared test for categorical variables. Corrected p values **p<0.01, ****p<0.0001.