(AS2) Comparison of Age and Modified Frailty index-5 as a Predictor of In-hospital Mortality for Patients with Complete Traumatic Cervical Spinal Cord Injury

Introduction: Increased clinical frailty, as measured by the mFI-5, and older age have been found to be associated with increased mortality in the setting of traumatic spinal cord injury (SCI). However, a comparison of the predictive power of each measure has not been completed. Therefore, in this study we aim to discern which patient factor is superior in a mortality predication model.

Methods: Using the 2010 to 2018 Trauma Quality Improvement Program (TQIP) database, we identified a cohort of adult (≥ 16 years) patients who sustained complete traumatic cervical SCI. We developed a regression model of mortality including either age, mFI-5, or the composite of age with mFI-5 adjusted for additional clinical covariates of interest. We conducted Receiver Operating Characteristic (ROC) analysis and Decision Curve Analysis (DCA) to compare models. Subgroup analysis was done by restricting the cohort to patients above 65 years.

Results: We identified 4,814 patients with mean age of 49, 63% mFI of 0, 22% mFI of 1, and 15% mFI ≥ 2. We found the area under the ROC curve (AUROC) for a model of age with mFI-5 (0.81 95%CI [0.79 0.84]) compared to a model with age alone (0.81 95%CI [0.79 0.83]) to be comparable (p = 0.57). Both models when compared to a predictive model with mFI-5 alone (0.75 95%CI [0.72 0.77]) were superior (p < 0.05). DCA also determined a predictive model with age or the composite of age with frailty has more clinical utility than mFI-5 alone. In an older age subgroup, ROC analysis and DCA also determined that a model with age and mFI-5 or age alone were similar (p = 0.22), and superior mFI-5 alone (p < 0.05).

Conclusion : In the setting of adult complete traumatic cervical SCI, our analysis suggests that age provides more predictive power in a statistical model for mortality than mFI-5.