Predictive utility of an adapted Marshall head CT classification scheme after traumatic brain injury

ABSTRACT Objective: To study the predictive relationship among persons with traumatic brain injury (TBI) between an objective indicator of injury severity (the adapted Marshall computed tomography [CT] classification scheme) and clinical indicators of injury severity in the acute phase, functional outcomes at inpatient rehabilitation discharge, and functional and participation outcomes at 1 year after injury, including death. Participants: The sample involved 4895 individuals who received inpatient rehabilitation following acute hospitalization for TBI and were enrolled in the Traumatic Brain Injury Model Systems National Database between 1989 and 2014. Design: Head CT variables for each person were fit into adapted Marshall CT classification categories I through IV. Main Measures: Prediction models were developed to determine the amount of variability explained by the CT classification categories compared with commonly used predictors, including a clinical indicator of injury severity. Results: The adapted Marshall classification categories aided only in the prediction of craniotomy or craniectomy during acute hospitalization, otherwise making no meaningful contribution to variance in the multivariable models predicting outcomes at any time point after injury. Conclusion: Results suggest that head CT findings classified in this manner do not inform clinical discussions related to functional prognosis or rehabilitation planning after TBI.Abbreviations: CT: computed tomography; DRS: disability rating scale; EGOS: extended Glasgow outcome scale; FIM: functional independence measure; NDB: National Data Base; PTA: posttraumatic amnesia; RLOS: rehabilitation length of stay; SPOS: semipartial omega squared statistic; TBI: traumatic brain injury; TBIMS: Traumatic Brain Injury Model Systems