Spine Surgeon NYU School of Medicine New Canaan, CT, US
Introduction: Several risk indices have been developed to guide the healthcare team in assessing the risk of surgical intervention on patient outcomes. However, there has yet to be an analysis of these risk indices in predictability of poor cost-effectiveness in adult spinal deformity surgery.
Methods: Operative ASD patients were included. Various risk indices (age, SpineSage, mFI (Passias et al.), CCI, NSQIP Risk Index, Comorbidity Score (ASD-CS), and ASA)were compared for predictability of overall, major, medical, surgical(infection), and CLAVIEN complications. Patients were stratified by High, Moderate, and Low risk in each individual index for cost-utility analysis. Costs were calculated using the PearlDiver database, with QALY calculated using normalized Oswetry Disability Index mapped to SF6D.
Results: 317 ASD patients met inclusion criteria. When assessing LOS, SICU stay, and EBL, SpineSage, ASA, ASD-CS, age and mFI correlated with SICU stay, while NSQIP Risk Index correlated with LOS and EBL. Only the mFI was predictive of mechanical complications (3.2, p=.018), reoperations (2.9, p=.03), and CLAVIEN I (1.4, p=.012). SpineSage was predictive of major (1.06, p=.046), ASD-CS predictive of CLAVIEN II, CCI major (1.4, p=.01), and CLAVIEN III (1.3, p=.03). NSQIP Risk Index and age were not predictive of any complications. An analysis of utility gain suggests patients moderate risk patients on average have the greatest amount of surgical improvement, as reflected by the highest QALYs gained. The mFI, ASD-CS, ASA, and CCI all showed low, moderate, high stratification can be used to predict cost utility of surgery, the NSQIP Risk Index showed the least predictive value while Spine SAGE trended towards projecting cost-utility.
Conclusion : The mFI was the only risk index predictive of mechanical complications and reoperations, while the NSQIP risk index showed the poorest predictive value for complications and cost-utility in adult spinal deformity surgery.
