• Stephanie J Tapp, Brook I Martin, Tor D Tosteson, Jon D Lurie, Milton C Weinstein, Richard A Deyo, Sohail K Mirza, and TostesonAnna N AANAMultidisciplinary Clinical Research Center in Musculoskeletal Diseases, The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA. Electronic address: anna.n.a.tosteson@dar.
• Multidisciplinary Clinical Research Center in Musculoskeletal Diseases, The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA.
• Spine J. 2018 Apr 1; 18 (4): 584-592.

Background ContextMinimally invasive lumbar spinal stenosis procedures have uncertain long-term value.PurposeThis study sought to characterize factors affecting the long-term cost-effectiveness of such procedures using interspinous spacer devices ("spacers") relative to decompression surgery as a case study.Study DesignModel-based cost-effectiveness analysis.Patient SampleThe Medicare Provider Analysis and Review database for the years 2005-2009 was used to model a group of 65-year-old patients with spinal stenosis who had no previous spine surgery and no contraindications to decompression surgery.Outcome MeasuresCosts, quality-adjusted life years (QALYs), and cost per QALY gained were the outcome measures.MethodsA Markov model tracked health utility and costs over 10 years for a 65-year-old cohort under three care strategies: conservative care, spacer surgery, and decompression surgery. Incremental cost-effectiveness ratios (ICER) reported as cost per QALY gained included direct medical costsfor surgery. Medicare claims data were used to estimate complication rates, reoperation, and related costs within 3 years. Utilities and long-term reoperation rates for decompression were derived frompublished studies. Spacer failure requiring reoperation beyond 3 years and post-spacer health utilities are uncertain and were evaluated through sensitivity analyses. In the base-case, the spacer failure rate was held constant for years 4-10 (cumulative failure: 47%). In a "worst-case" analysis, the 10-year cumulative reoperation rate was increased steeply (to 90%). Threshold analyses were performed to determine the impact of failure and post-spacer health utility on the cost-effectiveness of spacer surgery.ResultsThe spacer strategy had an ICER of $89,500/QALY gained under base-case assumptions, and remained under $100,000 as long as the 10-year cumulative probability of reoperation did not exceed 54%. Under worst-case assumptions, the spacer ICER was $482,000/QALY and fell below $100,000 only if post-spacer utility was 0.01 greater than post-decompression utility or the cost of spacer surgery was $1,600 less than the cost of decompression surgery.ConclusionsSpacers may provide a reasonably cost-effective initial treatment option for patients with lumbar spinal stenosis. Their value is expected to improve if procedure costs are lower in outpatient settings where these procedures are increasingly being performed. Decision analysis is useful for characterizing the long-term cost-effectiveness potential for minimally invasive spinal stenosis treatments and highlights the importance of complication rates and prospective health utility assessment.Copyright © 2017. Published by Elsevier Inc.

32 keywords...

hide…