On-admission anemia predicts mortality in COVID-19 patients: A single center, retrospective cohort study

Am J Emerg Med. 2021 Oct:48:140-147. doi: 10.1016/j.ajem.2021.03.083. Epub 2021 Mar 29.

Abstract

Objectives: We investigated the impact of anemia based on admission hemoglobin (Hb) level as a prognostic risk factor for severe outcomes in hospitalized patients with coronavirus disease 2019 (COVID-19).

Methods: A single-center, retrospective cohort study was conducted from a random sample of 733 adult patients (age ≥ 18 years) obtained from a total of 4356 laboratory confirmed SARS-CoV-2 cases who presented to the Emergency Department of Montefiore Medical Center between March-June 2020. The primary outcome was a composite endpoint of in-hospital severe outcomes of COVID-19. A secondary outcome was in-hospital all-cause mortality.

Results: Among the 733 patients included in our final analysis, 438 patients (59.8%) presented with anemia. 105 patients (14.3%) had mild, and 333 patients (45.5%) had moderate-severe anemia. Overall, 437 patients (59.6%) had a composite endpoint of severe outcomes. On-admission anemia was an independent risk factor for all-cause mortality, (Odds Ratio 1.52, 95% CI [1.01-2.30], p = 0.046) but not for composite severe outcomes. However, moderate-severe anemia (Hb < 11 g/dL) on admission was independently associated with both severe outcomes (OR1.53, 95% CI [1.05-2.23], p = 0.028) and mortality (OR 1.67, 95% CI [1.09-2.56], p = 0.019) during hospitalization.

Conclusion: Anemia on admission was independently associated with increased odds of all-cause mortality in patients hospitalized with COVID-19. Furthermore, moderate-severe anemia (Hb <11 g/dL) was an independent risk factor for severe COVID-19 outcomes. Moving forward, COVID-19 patient management and risk stratification may benefit from addressing anemia on admission.

Keywords: Anemia; COVID-19; Emergency department; Hypoxic respiratory failure; Mortality; Sepsis.

MeSH terms

  • Acute Kidney Injury / epidemiology*
  • Aged
  • Aged, 80 and over
  • Anemia / blood*
  • Anemia / therapy
  • Blood Transfusion / statistics & numerical data
  • COVID-19 / blood*
  • COVID-19 / mortality
  • Cause of Death
  • Cohort Studies
  • Female
  • Hemoglobins / metabolism
  • Hospital Mortality*
  • Hospitalization
  • Humans
  • Hypotension / epidemiology*
  • Intensive Care Units
  • Male
  • Middle Aged
  • Respiration, Artificial / statistics & numerical data
  • Respiratory Insufficiency / epidemiology*
  • Retrospective Studies
  • SARS-CoV-2
  • Severity of Illness Index
  • Shock, Septic / epidemiology*

Substances

  • Hemoglobins