160. Increasing cost efficiency in adult spinal deformity surgery: identifying predictors of lower total costs

Abstract

BACKGROUND CONTEXT Adult spinal deformity (ASD) surgery often involves complex deformity correction. It's unknown which baseline (BL) patient factors predict lower total costs in ASD surgery. PURPOSE Identify predictors of lower total surgery costs for ASD patients. STUDY DESIGN/SETTING Retrospective review of a prospective multicenter adult spinal deformity database. PATIENT SAMPLE A total of 311 operative ASD patients ≥18 years old with baseline and 3Y demographic, surgical, and frailty data. OUTCOME MEASURES Schwab sagittal vertebral axis (SVA) modifier grade, Owestry Disability Index (ODI), costs of ASD surgery, predictors of lower costs. METHODS Inclusion criteria included surgical ASD (scoliosis ≥20°, SVA ≥5cm, PT ≥25°, or thoracic kyphosis ≥60°) patients >18 years with available frailty, demographic, and radiographic data at BL and 1 year postop. Descriptive analyses assessed mean age, frailty, and surgical data. Total costs for surgery were calculated using the PearlDiver database. A conditional variable importance table used nonreplacement sampling set of 20,000 conditional inference trees to identify the top factors associated with lower cost surgery for low (LSVA), moderate (MSVA), and high (HSVA) Schwab modifier grades. LSVA were SVA 9.5 cm. Linear and logistic regression assessed the relationship between significant predictors and the odds of lower cost surgery. RESULTS Of the 322 total ASD patients, 322 met inclusion criteria. Descriptive statistics were: age 58.9 ± 14.9, 76% women, BMI 27.8 ± 6.2, 62% osteotomy, 54% decompression, and 11.0 ± 4.1 average levels fused. At 3yrfollow-up, the potential cost of ASD surgery ranged from $57,606.88 to $116,312.54. There were 152 LSVA patients, 53 MSVA patients, and 111 HSVA patients. For all patients, BL ODI 1.5 (2.62 [1.402-4.875], p=0.002], no previous spine surgery (1.77 [1.22-2.58], p=0.003), frailty scores 1.5 (6.76 [1.68-27.18] p=0.007), age 2.38 (3.93 [1.54-10.18] p=0.004), frailty scores CONCLUSIONS For ASD patients, low frailty, no prior spine surgery, no depression, and higher baseline SRS activity scores were predictive of lower total surgery costs. When assessed by baseline deformity, decreased frailty and the lack of comorbidities and risk factors such as cancer, smoking, or high BMI, were associated with lower costs. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.