Predicting survival after acute civilian penetrating brain injuries: The SPIN score

To identify predictors associated with survival in civilian penetrating traumatic brain injury (pTBI) utilizing a contemporary, large, diverse 2-center cohort, and to develop a parsimonious survival prediction score for pTBI.

Our cohort comprised 413 pTBI patients retrospectively identified from the local trauma registries at 2 US level 1 trauma centers, of which one was predominantly urban and the other predominantly rural. Predictors of in-hospital and 6-month survival identified in univariate and multivariable logistic regression were used to develop the simple Surviving Penetrating Injury to the Brain (SPIN) score.

The mean age was 33 ± 16 years and patients were predominantly male (87%). Survival at hospital discharge as well as 6 months post pTBI was 42.4%. Higher motor Glasgow Coma Scale subscore, pupillary reactivity, lack of self-inflicted injury, transfer from other hospital, female sex, lower Injury Severity Score, and lower international normalized ratio were independently associated with survival (all p < 0.001; model area under the curve 0.962). Important radiologic factors associated with survival were also identified but their addition to the full multivariable would have resulted in model overfitting without much gain in the area under the curve.

The SPIN score, a logistic regression-based clinical risk stratification scale estimating survival after pTBI, was developed in this large, diverse 2-center cohort. While this preliminary clinical survival prediction tool does not include radiologic factors, it may support clinical decision-making after civilian pTBI if external validation confirms the probability estimates.