Resident Physician University of New Mexico Albuquerque, NM, US
Disclosure(s):
Kavelin Rumalla, MD, MS: No financial relationships to disclose
Introduction: Type 2 odontoid fractures (T2OF) are a common cause of cervical instability. Definitive management (operative versus nonoperative), particularly in the elderly, is controversial. The Risk Analysis Index (RAI) is a robust index based on accumulation of deficits model of frailty. The present study analyzed the prognostic significance of RAI score on 30-day mortality after surgery for T2OF using the National Surgical Quality Improvement Program (NSQIP) database, 2015-2020.
Methods: The RAI (recalibrated RAI-administrative) was computed (scale 0-81) using established methodology. Predictive ability and diagnostic accuracy of RAI (vs. 5-factor modified frailty index, mFI-5) for 30-day mortality was assessed in logistic regression and receiver operating characteristic (ROC) curve analyses, respectively.
Results: Of 474 patients with surgically treated T2OF, the median age was 75 (IQR 66-81). In terms of frailty, 16.7% were robust (RAI 0-20), 63.7% were normal (RAI 21-30), 18.1% were frail (RAI 31-40), and 1.5% were severely frail (RAI 41+). Overall, 30-day mortality rate was 3.8%. A significant positive linear trend was noted between RAI and 30-day mortality (P < 0.001), which persisted within a subgroup of octogenarians/nonagenarians (N=118). By contrast, mFI-5 was not associated with 30-day mortality. In logistic regression, RAI was strongly associated with increasing odds of mortality for each 5 points above 20 (OR: 2.5, 95% CI: 1.7-3.6). In ROC analysis, RAI demonstrated excellent discrimination for 30-day mortality (C-statistic: 0.82, 95% CI: 0.74-0.90) as compared to subpar discrimination for mFI-5 (C-statistic: 0.60, 95 CI: 0.48-0.71).
Conclusion : Preoperative frailty (measured by RAI) is a valuable prognosticator with excellent discriminatory accuracy (C-statistic > 0.80) for 30-day mortality after surgical fixation for T2OF. The RAI-mortality association persisted in octogenarians/nonagenarians, supporting the hypothesis that frailty, not advanced age or comorbidities alone (mFI-5), predict survival. We hope the findings prompt further study of frailty (by RAI) in other patient populations, prospective registries, and quality improvement interventions.
