Longitudinal lab test analysis confirms pre-existing anemia as a severe risk factor for post-viral clearance hospitalization in COVID-19 patients

Lenehan, Patrick; Ramudu, Eshwan; Venkatakrishnan, AJ; Berner, Gabriela; McMurry, Reid; O039, John; Horo,; Badley, Andrew D; Morice, William G; Halamka, John; Soundararajan, Venky

BackgroundAs the number of new and recovering COVID-19 cases continues to rise, it has become evident that patients can experience symptoms and complications after viral clearance. Clinical biomarkers characterizing patients who are likely to experience these prolonged effects are unknown. MethodsWe conducted a retrospective study to compare longitudinal lab test measurements (hemoglobin, hematocrit, estimated glomerular filtration rate, serum creatinine, and blood urea nitrogen) in patients rehospitalized after PCR-confirmed SARS-CoV-2 clearance (n=104) versus patients not rehospitalized after viral clearance (n=278). FindingsCompared to patients who were not rehospitalized after PCR-confirmed viral clearance, those who were rehospitalized had lower median hemoglobin levels in the year prior to COVID-19 diagnosis (cohens D = -0.50; p=1.2x10-3) and during the active infection window (cohens D = -0.71; p=4.6x10-8). Patients hospitalized after viral clearance were also more likely to be diagnosed with moderate or severe anemia during the active infection window (OR = 2.18; p = 4.99x10-9). ConclusionsThe occurrence of moderate or severe anemia in hospitalized COVID-19 patients is strongly associated with rehospitalization after viral clearance. Whether interventions to mitigate anemia can improve long term outcomes of COVID-19 patients should be further investigated. FundingThis study was funded by nference.