Nutritional deficiency anemia and post‐acute sequelae in patients with severe acute respiratory syndrome coronavirus 2 infection: A six‐month retrospective cohort analysis of 30 892 patients

The effect of anemia on the post‐acute outcome of patients with severe acute respiratory syndrome coronavirus 2 infection was unclear. This study aimed to investigate the potential association between nutritional deficiency anemia (NDA) status and post‐acute sequelae of patients with SARS‐CoV‐2 infection. This retrospective cohort study included patients with coronavirus disease (COVID‐19) from January 1, 2022 to November 30, 2022 using the TriNetX research network. The patients were grouped into the NDA group comprising patients diagnosed with NDA and the control group comprising patients without NDA, and propensity score matching (PSM) was performed to balance the two groups. The primary outcome was a composite of post‐COVID‐19 condition, all‐cause hospitalization, and all‐cause death. The secondary outcomes were any individual outcomes of the primary composite. The follow‐up period was set at 90–180 days after COVID‐19 diagnosis. Two cohorts comprising 15 446 nonhospitalized patients with COVID‐19 in each group with balanced baseline characteristics were created using PSM. During the follow‐up period, the NDA group demonstrated a higher risk of the composite primary outcome, including post‐COVID‐19 condition, all‐cause hospitalization, or all‐cause death (hazard ratio [HR], 1.896; 95% confidence interval [CI] = 1.757–2.045). Regarding secondary outcomes, the NDA group was associated with worse outcomes, including post‐COVID‐19 condition (HR, 1.992; 95% CI = 1.403–2.828), all‐cause hospitalization (HR, 1.856; 95% CI = 1.714–2.009), and all‐cause death (HR, 3.922; 95% CI = 2.910–5.285) compared to the control group. Among nonhospitalized patients with COVID‐19, NDA was associated with a higher risk of post‐COVID‐19 condition, all‐cause hospitalization, and all‐cause death during the 90–180‐day follow‐up period.