Assessment of a Novel Adult Cervical Deformity Frailty Index as a Component of Preoperative Risk Stratification

Objective To determine the value of a novel adult cervical deformity frailty index (CD-FI) in preoperative risk stratification. Methods We reviewed a prospective, multicenter database of adults with cervical spine deformity. We selected 40 variables to construct the CD-FI using a validated method. Patients were categorized as not frail (NF) (<0.2), frail (0.2–0.4), or severely frail (SF) (>0.4) according to CD-FI score. We performed multivariate logistic regression to determine the relationships between CD-FI score and incidence of complications, length of hospital stay, and discharge disposition. Results Of 61 patients enrolled from 2009 to 2015 with at least 1 year of follow-up, the mean CD-FI score was 0.26 (range 0.25–0.59). Seventeen patients were categorized as NF, 34 as frail, and 10 as SF. The incidence of major complications increased with greater frailty, with a gamma correlation coefficient of 0.25 (asymptotic standard error, 0.22). The odds of having a major complication were greater for frail patients (odds ratio 4.4; 95% confidence interval 0.6–32) and SF patients (odds ratio 43; 95% confidence interval 2.7–684) compared with NF patients. Greater frailty was associated with a greater incidence of medical complications and had a gamma correlation coefficient of 0.30 (asymptotic standard error, 0.26). Surgical complications, discharge disposition, and length of hospital stay did not correlate significantly with frailty. Conclusions Greater frailty was associated with greater risk of major complications for patients undergoing cervical spine deformity surgery. The CD-FI may be used to improve the accuracy of preoperative risk stratification and allow for adequate patient counseling.