Abnormal Serum Albumin, Alanine Aminotransferase, and Blood Urea Nitrogen are Associated with Higher Risks for Mechanical Ventilation and In-Hospital Mortality in COVID-19 Positive US Veterans

Background: Since the first reported case of Coronavirus Disease 2019 (COVID-19), clinicians and scientists have been challenged to contrive ideal prevention, detection, and treatment strategies. As the death toll surpasses 1 million in the United States, identifying disease risk factors, specifically those risks related to severe disease manifesting as in-hospital mortality and invasive mechanical ventilation (MV), becomes crucial. Objectives: This study evaluated the association between abnormal blood biochemical markers, specifically albumin, alanine aminotransferase (ALT), creatinine, serum sodium, and blood urea nitrogen (BUN), to MV and in-hospital mortality in COVID-19 positive United States Veterans. Design: We performed a retrospective cohort analysis on 298 760 US veterans admitted to any national Veterans Affairs Hospital (VHA) with a positive COVID-19 test from March 1, 2020, to August 31, 2021, resulting in a total of 30 729 patients. Methods: A selection of patient-specific and COVID-19 test-related data was collected from the COVID-19 Shared Data Resources sourced from the VHA's Corporate Data Warehouse. These data were statistically analyzed using multivariable Cox regression models. Results: Patients with lower albumin (23 mg/dL), creatinine (>1.5 mg/dL), and ALT (>40 U/L) levels had increased risks for MV (29%, 40%, 20%, 26%) and in-hospital mortality (46%, 69%, 23%, 13%), respectively. Interestingly, patients with lower BUN (