An Economic Analysis of Early and Late Complications After Adult Spinal Deformity Correction.

Abstract

Retrospective cohort. Adult spinal deformity (ASD) corrective surgery is often a highly invasive procedure portending patients to both immediate and long-term complications. Therefore, we sought to compare the economic impact of certain complications before and after 2 years. ASD patients with minimum 3-year data included. Complication groups were defined as follows: any complication, major, medical, mechanical, radiographic, and reoperation. Complications stratified by occurrence <i>before</i> or <i>after</i> 2 years postoperatively. Published methods converted ODI to SF-6D to QALYs. Cost was calculated using CMS.gov definitions. Marginalized means for utility gained and cost-per-QALY were calculated via ANCOVA controlling for significant confounders. 244 patients included. <i>Before</i> 2Y, complication rates: 76% ≥1 complication, 18% major, 26% required reoperation. <i>After</i> 2Y, complication rates: 32% ≥1 complication, 4% major, 2.5% required reoperation. Major complications after 2 years had worse cost-utility (.320 vs .441, <i>P</i> = .1). Patients suffering mechanical complications accrued the highest overall cost ($130,482.22), followed by infection and PJF for complications <i>before</i> 2 years. Patients suffering a mechanical complication <i>after</i> 2 years had lower cost-utility ($109,197.71 vs $130,482.22, <i>P</i> = .041). Patients developing PJF <i>after</i> 2 years accrued a better cost-utility ($77,227.84 vs $96,873.57; <i>P</i> = .038), compared to PJF <i>before</i> 2 years. Mechanical complications had the single greatest impact on cost-utility after adult spinal deformity surgery, but less so after 2 years. Understanding the cost-utility of specific interventions at certain timepoints may mitigate economic burden and prophylactic efforts should strategically be made against early mechanical complications.