Anemia during SARS-CoV-2 infection is associated with rehospitalization after viral clearance

Lenehan, Patrick J.; Ramudu, Eshwan; Venkatakrishnan, A. J.; Berner, Gabriela; McMurry, Reid; O’Horo, John C.; Badley, Andrew D.; Morice, William; Halamka, John; Soundararajan, Venky

COVID-19 patients can experience symptoms and complications after viral clearance. It is important to identify clinical features of patients who are likely to experience these prolonged effects. We 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). Rehospitalized patients had lower median hemoglobin levels in the year prior to COVID-19 diagnosis (cohen’s D = -0.50; p=1.2x10-3) and during their active SARS-CoV-2 infection (cohen’s D = -0.71; p=4.6x10-8). Rehospitalized patients were also more likely to be diagnosed with moderate or severe anemia during their active infection (OR = 2.18; p = 4.99x10-9). These findings suggest that anemia-related laboratory tests should be considered in risk stratification algorithms for COVID-19 patients.