Red Cell Distribution Width and Its Association with Neonatal Bacteremia: A Case-Control Study

Background: Bacteremia is a major cause of prolonged hospital stay and mortality in neonates and its early diagnosis remains a challenge to pediatricians. Red cell distribution width (RDW) is a component of a complete blood count test which is accessible and inexpensive and has been reported to be a possible diagnostic marker for neonatal bacteremia. This study determined the association of RDW with neonatal bacteremia in term and preterm neonates. Methodology: This is a retrospective case-control study of 26 bacteremic neonates as cases and 104 non-bacteremic neonates, either symptomatic or with risk factors for bacteremia, as controls. Included newborns were seen between January 1, 2010 to September 30, 2021. Laboratory data obtained were CBC, C-reactive protein and blood culture. Results: RDW values between bacteremic and non-bacteremic neonates were not significantly different. There was an association between RDW and neonatal bacteremia at an RDW level of > 16.1, where the likelihood of bacteremia was three times higher compared with lower RDW values. Significantly lower levels of hemoglobin, hematocrit, RBC count, WBC count, platelet count, MCH and MCHC, and a higher CRP level were seen among bacteremic neonates compared to those who were not. The median RDW for both term and preterm neonates was close to 16, with a narrow inter-quartile range at 1 and 2 for controls and cases, respectively. The range (minimum to maximum) of RDW values of bacteremic preterm neonates was more variable than those of term neonates. Using RDW to detect bacteremia, it had an equivocal discriminatory power or AUC of 0.6056. We found insufficient evidence to demonstrate a correlation between RDW and other CBC parameters, except for MCHC. For MCHC, the results suggest a very weak and indirect correlation. Conclusion: RDW was not significantly different between bacteremic and non-bacteremic neonates, but there was a suggested association between RDW and bacteremia at an RDW level of > 16.1, at which level there was a 3-fold risk for bacteremia.