Development and validation of a nomogram for prediction of survival in adolescent spinal cord injury patients

Among all pediatric injuries, spinal cord injuries in children carry the highest morbidity and mortality yet literature on pediatric spinal cord injury remains sparse. This study aims to investigate factors associated with survival following spinal cord injury in the adolescent population.

Adolescent patients (defined in this study as 15-18 years of age) with a spinal cord injury were identified from the National Spinal Cord Injury Statistical Center (NSCISC) database between 1972 and 2021. Significant predictors of overall survival (OS) were identified with univariate and multivariable Cox proportional hazard modeling. Such variables were incorporated into a predictive nomogram for one-, two-, and three-year survival probability. The reliability of the nomogram was evaluated with receiver operating characteristic curves, calibration curves, and decision curves for training and validation datasets. Two way ANOVAs were run to evaluate age-related differences in survival across all included clinical characteristics.

A total of 1,208 patients were identified in the cohort, which included 966 in the training cohort and 242 in the validation cohort. In the univariate analyses, there was a significant predictive value of increasing age (hazard ratio [1] 1.080 [1.000-1.167], p = 0.049), African-American race (HR 1.338 [1.111-1.613], p = 0.002), and ventilator dependence (HR 3.440 [2.516-4.702], p < 0.001) on reduced survival. All variables deemed significant in the univariate analysis remained significant predictors of poor survival in the multivariable analysis, including increasing age (HR 1.106 [1.018-1.201], p = 0.017), African-American race (HR 1.354 [1.119-1.638]), and ventilator dependence (HR 3.565 [2.559-4.969], p < 0.001). A nomogram was developed to assess the probability of one-, two-, and three-year survival based on the model incorporating age, African-American race, and ventilator dependence. In the validation dataset, the calibration curves demonstrated good fit of the predicted outcomes to the observed outcomes at one-, two- and three-years with C-indices of 0.720, 0.713, and 0.696 respectively.

This present study generated a nomogram for survival in adolescent spinal cord injury. We highlight statistically validated risk factors, including age, African American race, and ventilator dependence, which are significant predictors of poor survival. These data provide a clinical adjunct to assess survival probability in adolescents with spinal cord injury and may aid with clinical decision-making.