Natural Progression of Routine Laboratory Markers following Spinal Trauma: A Longitudinal, Multi-Cohort Study

ObjectiveTo track and quantify the natural course of hematological markers over the first year following spinal cord injury. MethodsData on hematological markers, demographics, and injury characteristics were extracted from medical records of a clinical trial (Sygen) and an ongoing observational cohort study (Murnau Study). The primary outcomes were concentration/levels/amount of commonly collected hematological markers at multiple time-points. Two-way ANOVA and mixed-effects regression techniques were used to account for the longitudinal data and adjust for potential confounders. Trajectories of hematological markers contained in both data sources were compared using the slope of progression. ResultsAt baseline ([≤] 2 weeks post-injury), most hematological markers were at pathological levels, but returned to normal values over the course of six to twelve months post-injury. The baseline levels and longitudinal trajectories were dependent on injury severity. More complete injuries were associated with more pathological values (e.g. hematocrit, ANOVA test; Chisq = 77.10, df = 3, adjusted p-value<0.001, and Chisq = 94.67, df = 3, adjusted p-value<0.001, in the Sygen and Murnau studies, respectively). Comparing the two databases revealed some differences in the hematological markers, which are likely attributable to differences in study design, sample size, and standard of care. ConclusionsDue to trauma-induced physiological perturbations, hematological markers undergo marked changes over the course of recovery, from initial pathological levels that normalize within a year. The findings from this study are important as they provide a benchmark for clinical decision making and prospective clinical trials. All results can be interactively explored on the Haemosurveillance website (https://jutzelec.shinyapps.io/Haemosurveillance/). Code availabilityhttps://github.com/jutzca/Systemic-effects-of-Spinal-Cord-Injury