Cost-effectiveness Improves for Operative vs Nonoperative Treatment of Adult Symptomatic Lumbar Scoliosis at Eight-Year Follow-up.

Abstract

Study designSecondary data analysis of the NIH sponsored study on Adult Symptomatic Lumbar Scoliosis (ASLS).ObjectivesThe purpose of this study is to perform a cost-effectiveness analysis comparing operative versus non-operative care for ASLS eight years after enrollment.Summary of background dataA prior cost-effectiveness analysis of the current cohort comparing operative to non-operative care at five years after enrollment showed and ICER of $44,033 in the As-Treated analysis and a ICER of $27,480 in the Intent-to-treat analysis.MethodsData was collected every three months for the first two years, then every six months for the remainder of the study. Data included use of non-operative modalities, medications and employment status. Costs for index and revision surgeries and non-operative modalities were determined using Medicare Allowable rates. Medication costs were determined using the RedBook and indirect costs were calculated based on reported employment status and income. Quality Adjusted Life Years (QALY) was determined using the SF6D.ResultsThere were 101 cases in the Operative (Op) and 103 in the Non-operative (Non-Op) group with complete eight year data. Thirty-eight patients (37%) in the Non-Op group had surgery from 3 to 72 months after enrollment. An As-Treated analysis including only cases who never had surgery (N=65) or cases with complete eight-year post-operative data (N=101) showed that operative treatment was favored with an ICER of $20,569 per QALY gained which is within Willingness-to-Pay (WTP) thresholds. An Intent-to-Treat analysis demonstrated greater QALY gains and lower cost in the Op group (ICER = $-13,911). However, Intent-to-Treat analysis is influenced by Non-Op patients who crossed over to operative treatment at variable times during follow-up.ConclusionOperative treatment was more cost-effective than non-operative treatment for ASLS at eight-year follow-up. The ICER continued to improve as compared to the five-year values ($20,569 vs. $44,033).