P110. Improvements in cost effectiveness of adult cervical deformity corrective surgery over time: Analysis of a prospective adult cervical deformity database

Abstract

<h3>BACKGROUND CONTEXT</h3> As operative measures and field knowledge advance, we hope that there is an improvement in outcomes for adult cervical deformity surgery. This improvement can be described by cost effectiveness, which encompasses operative cost, poor outcomes such as complications, and patient-reported measures. <h3>PURPOSE</h3> To determine whether surgical methods have improved by reducing the instance of complications and cost of cervical deformity (CD) surgery while improving patient reported outcomes. <h3>STUDY DESIGN/SETTING</h3> Retrospective cohort study of a prospectively enrolled multicenter CD database. <h3>PATIENT SAMPLE</h3> A total of 132 CD patients. <h3>OUTCOME MEASURES</h3> Complications, Reoperations, EQ5D, total cost, utility gained, Quality Adjusted Life Years (QALYs), Distal Junctional Kyphosis (DJK) <h3>METHODS</h3> CD patients with baseline (BL) and up to 2-year (2Y) HRQL data from 2013-2017 were included. Data from 2017 was combined with 2016 due to an incomplete year. ANCOVA found estimated marginal means of complications and reoperations adjusting for BL age, sex, surgical approach, and invasiveness. Cost was calculated using PearlDiver and assessed for Complications/Major Complications and Comorbidities according to CMS.gov. QALYs were calculated from EQ5D improvement and utilized 3% discount rate for residual decline to life expectancy (LE, 78.7 years). This data represents national average Medicare costs by surgical approach, complications and revision status. Trendline analysis noted changes over time. In a sub-analysis relating to a previous study, patients were identified by amount of risk factors for revision (UIV>C3, LIV>T3, C2-T3 SVA<46.7°, C2-C7 SVA>57.6°, CTPA>7.8°, and C2S<60.4) met. QALYs were calculated from NDI improvement in this analysis. <h3>RESULTS</h3> There were 132 patients included in the study. Of these, 24 had surgery in 2013, 52 in 2014, 24 in 2015, and 32 in 2016. There was a trend downward with respect to 2-year total cost over the years (2013: $42,754; 2016: $39,155), as the trendline showed a yearly decrease of $2,753 (R2=0.6966). Concurrently, there was an increase EQ5D improvement after 2-year (2013: 0.0113; 2016: 0.0697). This resulted in an increase of 0.0172 per year in QALYs gained at 2-year (R2=0.8109) and a 0.2358 increase per year in QALYs gained at LE (R2=0.8533). Thus, there was a decrease in cost per QALY at 2-year of $6,057 per year (R2=0.0497) and at LE of $67,478 per year (R2=06588). Total cost at 2-year for those with Distal Junctional Kyphosis was $98,357 vs $59,129 for non-DJK; cost per QALY was $46,932 vs $28,571, respectively. Sub-analysis indicated increasing risk criteria were associated with major complications (2.085 [1.057-4.114], p=0.034) and reoperations (4.267 [1.604-11.352], p=0.004). Cost increased by $7,167 per factor (R2=0.9901). Patients with fewer factors had greater NDI improvement than high risk (1: -24.6; 2: -14.8; 3: -15.6; 4: -3.8, p=0.023). This translated to low cost per QALY at 2-year for 1 factor ($45,787), with worse cost efficiency per factor (2: $90,117; 3: $103,543; 4: $525,472). <h3>CONCLUSIONS</h3> Between 2013 and 2017, total cost for cervical deformity surgery decreased – possibly due to complication and risk reductions – while EQ5D improvement has increased, leading to improved cost effectiveness. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.