Comparing routine hematological parameters on COVID-19, bacterial infections, and coinfection in elderly severe community-acquired pneumonia, a retrospective study in primary hospitals

A BSTRACT Objective: This study aimed to compare the differences in routine hematological parameters upon admission in elderly patients with severe community-acquired pneumonia (CAP) caused by COVID-19, bacterial infections, and coinfection. Methods: A retrospective study was conducted on elderly patients with severe CAP caused by COVID-19, bacterial infections, and coinfection. Routine laboratory hematological parameters were compared. Results: Pairwise comparisons revealed that LY and MY counts and PT levels were the highest in the bacteria group, while Mg levels were the lowest in the COVID-19 group, and IL-6 levels were the lowest in the coinfection group. WBC counts, Ca, and P levels were higher in the bacteria group than in the COVID-19 group, and APTT and ALB levels were significantly elevated in the bacteria group compared to the coinfection group. Fe levels were lower in the coinfection group than in the COVID-19 group. Conclusion: Our results indicate that in elderly patients, these hematological parameters are associated with severe CAP of different etiologies and can aid in diagnosis, along with clinical signs, as part of clinical prediction rules.