Average Lifetime Hemoglobin Concentration Improves Prediction of Cognitive Outcomes in Pediatric Patients with Sickle Cell Anemia

Background: Sickle cell anemia (SCA) is associated with cognitive challenges that often worsen as children age. Previous work has established relationships between hematological markers of disease severity (i.e., hemoglobin concentration) and various neurological outcomes, including cognitive impairment. However, most studies have related static, often isolated hemoglobin concentration (Hb) values obtained from a single time-point closest to data collection. Studies of pediatric patients with phenylketonuria and Type I diabetes have demonstrated that longitudinal change and variability in phenylalanine and glucose, respectively, are better indicators of neurological and cognitive outcomes than a single value alone. Our study aimed to be the first study of pediatric patients with SCA to examine the extent to which indices of Hb control (e.g., lifetime average and variability), collected routinely in this patient group, may provide additional prognostic information.