Introduction: Cost effectiveness research in spine surgery has been a prominent focus over the last decade. However, there has yet to be a standardized method developed for calculation of costs in such studies. This lack of a standardized costing methodology may lead to conflicting conclusions on the cost effectiveness of an intervention for a specific diagnosis. The primary objective is to systematically review all cost effectiveness studies published on spine surgery and compare and contrast various costing methodologies used.

Methods: All cost effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis (CEA) registry database (Tufts Medical Center, Institute for Clinical Research and Health Policy) and the Medline database. Each article was reviewed for the study subject, methodology, and results. Data were collected from each study, including costs, intervention, cost calculation method, perspective of cost calculation, and definitions of direct and indirect costs if available.

Results: Thirty-seven cost effectiveness studies on spine surgery were included in the present study. Twenty-seven (73%) of the studies involved the lumbar spine and the remaining ten (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case costing database (CCD), 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the National Health Service (NHS) reimbursement system, 2 (5%) used a Dutch reimbursement system, 1 (3%) used the United Kingdom Department of Health data, and 1 (3%) used the Tricare Military Reimbursement system. Nineteen (51%) studies completed their cost analysis from the societal perspective, 11 from the hospital perspective (30%), and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 16 (42%) reported actual indirect costs.

Conclusions: Changes in cost have a direct impact on the value equation for concluding whether an intervention is cost effective. It is essential to develop a standardized, accurate means of calculating costs. Comparability and transparency are essential such that studies can be compared properly and policy makers can be appropriately informed when making decisions for our healthcare system based on the results of these studies.

Patient Care: Costs are an important aspect of clinical, insurance coverage, and payment decisions in healthcare. Specifically, cost containment has become a prominent issue in United States (U.S.) healthcare policy. With the continued elevation of healthcare expenditures, medical and surgical interventions are being increasingly scrutinized for their cost effectiveness to both the patient and provider. Given equal effectiveness between two procedures for the same medical or surgical indication, patients, providers, and payers will choose the less expensive procedure. It is the transparency of costs that may benefit both the public and private sectors. A major limitation of existing cost effectiveness studies is the heterogeneous way in which costs are defined and calculated, as there has yet to be a standardized approach for conducting a cost effectiveness study. This limitation leads to great difficulty interpreting the results of CUAs and the potential for biased results. The purpose of this study was to systematically review all cost effectiveness studies in the spine surgery literature, identify how costs were defined and calculated, and compare different cost methodologies among studies analyzing the same intervention. Understanding these differences will aid future investigators in performing more standardized cost effectiveness analyses.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand how costs are calculated, the terms utilized, and perspective taken in cost effectiveness research and 2) Discuss why it is essential that researchers be transparent about how costs are calculated and from what perspective.

References: 1. Adogwa O, Parker SL, Shau DN, Mendenhall SK, Aaronson O, Cheng JS, et al: Cost per quality-adjusted life year gained of revision neural decompression and instrumented fusion for same-level recurrent lumbar stenosis: defining the value of surgical intervention. J Neurosurg Spine 16:135–140, 2012 2. Adogwa O, Parker SL, Shau DN, Mendenhall SK, Devin CJ, Cheng JS, et al: Cost per quality-adjusted life year gained of laminectomy and extension of instrumented fusion for adjacent-segment disease: defining the value of surgical intervention. J Neurosurg Spine 16:141–146, 2012 3. Adogwa O, Parker SL, Davis BJ, Aaronson O, Devin C, Cheng JS, et al: Cost-effectiveness of transforaminal lumbar interbody fusion for grade I degenerative spondylolisthesis. J Neurosurg Spine 15:138-143, 2011 4. Angevine PD, Zivin JG, McCormick PC: Cost-effectiveness of single-level anterior cervical discectomy and fusion for cervical spondylosis. Spine (Phila Pa 1976) 30:1989-97, 2005 5. Bell CM, Urbach DR, Ray DG, Bayoumi A, Rosen AB, Greenberg D, et al: Bias in published cost effectiveness studies: systematic review. BMJ 332:699-703, 2006 6. Bhadra AK, Raman AS, Casey AT, Crawford RJ: Single-level cervical radiculopathy: clinical outcome and cost-effectiveness of four techniques of anterior cervical discectomy and fusion and disc arthroplasty. Eur Spine J 18:232-7, 2009 7. Brauer CA, Rosen AB, Olchanski NV, Neumann PJ: Cost-utility analyses in orthopaedic surgery. J Bone Joint Surg Am 87:1253–9, 2005 8. Brown MM, Brown GC, Sharma S, Landy J: Health care economic analyses and value-based medicine. Surv Ophthalmol 48:204-23, 2003 9. Carreon LY, Anderson PA, Traynelis VC, Mummaneni PV, Glassman SD: Cost Effectiveness of Single-Level Anterior Cervical Discectomy and Fusion Five Years After Surgery. Spine (Phila Pa 1976) 38:471-5, 2013 10. Carreon LY, Glassman SD, Djurasovic M, Campbell MJ, Puno RM, Johnson JR, et al: RhBMP-2 Versus Iliac Crest Bone Graft for Lumbar Spine Fusion in Patients Over 60 Years of Age: A Cost Utility Study. Spine 34:238–243, 2009 11. Centers for Medicare and Medicaid: 2012 Health Expenditure Highlights. (http://www.cms.gov/Research-Statistics-Data-and-Systems/Statistics-Trends-and-Reports/NationalHealthExpendData/downloads/highlights.pdf) [Accessed January 15, 2014] 12. Dagenais S, Roffey DM, Wai EK, Haldeman S, Caro J: Can cost utility evaluations inform decision making about interventions for low back pain? Spine J 9:944–57, 2009 13. Fehlings MG, Jha NK, Hewson SM, Massicotte EM, Kopjar B, Kalsi-Ryan S: Is surgery for cervical spondylotic myelopathy cost-effective? A cost-utility analysis based on data from the AOSpine North America prospective CSM study. J Neurosurg Spine 17:89-93, 2012 14. Fernandez-Fairen M, Murcia A, Torres A, Hernandez-Vaquero, Menzie AM: Is Anterior Cervical Fusion With a Porous Tantalum Implant a Cost-Effective Method to Treat Cervical Disc Disease With Radiculopathy? Spine 37:1734–41, 2012 15. Freeman BJC, Steele NA, Sach TH, Hegarty J, Soegaard R: ISSLS Prize Winner: Cost-Effectiveness of Two Forms of Circumferential Lumbar Fusion. Spine 32:2891–2897, 2007 16. Fritzell P, Berg S, Borgstrom F, Tullberg T, Tropp H: Cost effectiveness of disc prosthesis versus lumbar fusion in patients with chronic low back pain: randomized controlled trial with 2-year follow-up. Eur Spine J 20:1001–11, 2011 17. Ghogawala Z, Martin B, Benzel EC, Dziura J, Magge SN, Abbed KM, et al: Comparative effectiveness of ventral vs dorsal surgery for cervical spondylotic myelopathy. Neurosurgery 68:622-30, 2011 18. Glassman SD, Polly DW, Dimar JR, Carreon LY: The cost effectiveness of single-level instrumented posterolateral lumbar fusion at five years after surgery. Spine (Phila Pa 1976) 37:769-74, 2012 19. Gluck ME: Research Insights: Incorporating costs into comparative effectiveness research. (www.AcademyHealth.org) [Accessed January 15, 2014] 20. Hansson E, Hansson T: The cost–utility of lumbar disc herniation surgery. Eur Spine J 16:329–37, 2007 21. Healthcare Cost and Utilization Project (HCUP): Cost-to-charge ratio files. Rockville, MD, Agency for Healthcare Research and Quality. (http://www.hcup-us.ahrq.gov/db/state/costtocharge.jsp) [Accessed January 15, 2014] 22. Kepler CK, Wilinson SM, Radcliff KE, Vaccaro AR, Anderson DG, Hilibrand AS, et al: Cost-utility analysis in spine care: a systematic review. Spine J 12:676-90, 2012 23. Kim S, Mortaz Hedjri S, Coyte PC, Rampersaud YR: Cost-utility of lumbar decompression with or without fusion for patients with symptomatic degenerative lumbar spondylolisthesis. The Spine Journal 12:44-54, 2012 24. Kuntz KM, Snider RK, Weinstein JN, Pope MH, Katz JN: Cost-effectiveness of fusion with and without instrumentation for patients with degenerative spondylolisthesis and spinal stenosis. Spine 25:1132-1139, 2000 25. Launois R, Henry B, Marty JR, Gersberg M, Lassale C, Benoist M, et al: Chemonucleolysis versus surgical discectomy for sciatica secondary to lumbar disc herniation: A cost and quality of life evaluation. Pharmaeconomics 6:453-463, 1994 26. Malter AD, Larson EB, Urban N, Deyo RA: Cost-effectiveness of lumbar discectomy for the treatment of herniated intervertebral disc. Spine 21:1048-54, 1996 27. Menzin J, Zhang B, Neumann PJ, Lines LM, Polly DW, Barnett-Myers S, Fontes R, Traynelis VC: A health-economic assessment of cervical disc arthroplasty compared with allograft fusion. Techniques in Orthopaedics 25:133-137, 2010 28. North RB, Kidd D, Shipley J, Taylor RS: Spinal Cord Stimulation versus Reoperation for Failed Back Surgery Syndrome: a Cost Effectiveness and Cost Utility Analysis Based on a Randomized, Controlled Trial. Neurosurgery 61:361–69, 2007 29. Parker SL, Adogwa O, Bydon A, Cheng J, McGirt MJ: Cost-Effectiveness of Minimally Invasive versus Open Transforaminal Lumbar Interbody Fusion for Degenerative Spondylolisthesis Associated Low-Back and Leg Pain Over Two Years. World Neurosurg 78:178-84, 2012 30. Parker SL, McGirt MJ: Determination of the Minimum Improvement in Pain, Disability, and Health State Associated With Cost-Effectiveness: Introduction of the Concept of Minimum Cost-Effective Difference. Neurosurgery 71:1149–1155, 2012 31. Parker SL, Fulchiero EC, Davis BJ, Adogwa O, Aaronson OS, Cheng JS, et al: Cost-effectiveness of multilevel hemilaminectomy for lumbar stenosis–associated radiculopathy. The Spine Journal 11:705–711, 2011 32. Parker SL, Adogwa O, Davis BJ: Cost-utility Analysis of Minimally Invasive Versus Open Multilevel Hemilaminectomy for Lumbar Stenosis. J Spinal Disord Tech 26:42–7, 2012 33. Qureshi SA, McAnany S, Goz V, Koehler SM, Hecht AC: Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion: clinical article. J Neurosurg Spine 19:546-54, 2013 34. Rasanen P, Ohman J, Sintonen H, Ryynanen OP, Koivisto AM, Blom M, et al: Cost–utility analysis of routine neurosurgical spinal surgery. J Neurosurg Spine 5:204–209, 2006 35. Rihn JA, Berven S, Allen T, Phillips FM, Currier BL, Glassman SD, et al: Defining value in spine care. American Journal of Medical Quality 24:4S–14S, 2009 36. Rihn JA, Currier BL, Phillips FM, Glassman SD, Albert TJ: Defining the value of spine care. J Am Acad Orthop Surg 21:419-26, 2013 37. Rivero-Arias O, Campbell H, Gray A, Fairbank J, Frost H, Wilson-MacDonald J: Surgical stabilisation of the spine compared with a programme of intensive rehabilitation for the management of patients with chronic low back pain: cost utility analysis based on a randomised controlled trial. BMJ 330:1239, 2005 38. Sanborn, MR, Thawani JP, Whitmore RG, Shmulevich M, Hardy B, Benedetto C, et al: Cost-effectiveness of confirmatory techniques for the placement of lumbar pedicle screws. Neurosurg Focus 33:E12, 2012 39. Soegaard R, Bunger CE, Christiansen T, Hoy K, Eiskjaer SP, Christensen FB: Circumferential Fusion Is Dominant Over Posterolateral Fusion in a Long-term Perspective. Spine 32:2405–14, 2007 40. Tosteson AN, Tosteson TD, Lurie JD, Abdu W, Herkowitz H, Andersson G, et al: Comparative effectiveness evidence from the spine patient outcomes research trial: Surgical versus nonoperative care for spinal stenosis, degenerative spondylolisthesis, and intervertebral disc herniation. Spine (Phila Pa 1976) 36:2061-68, 2012. 41. Tosteson AN, Lurie JD, Tosteson TD, Skinner JS, Herkowitz H, Albert T, et al: Surgical treatment of spinal stenosis with and without degenerative spondylolisthesis: cost-effectiveness after 2 years. Ann Intern Med 149:845-53, 2008 42. Tosteson AN, Skinner JS, Tosteson TD, Lurie JD, Andersson GB, Berven S, et al: The cost effectiveness of surgical versus nonoperative treatment for lumbar disc herniation over two years: evidence from the Spine Patient Outcomes Research Trial (SPORT). Spine 33:2108-15, 2008 43. Tso P, Walker K, Mahomed N, Coyte PC, Rampersaud YR: Comparison of lifetime incremental cost:utility ratios of surgery relative to failed medical management for the treatment of hip, knee and spine osteoarthritis modelled using 2-year postsurgical values. Can J Surg 55:181-90, 2012 44. Tumeh JW, Moore SG, Shapiro R, Flowers CR: Practical approach for using Medicare data to estimate costs for cost–effectiveness analysis. Expert Rev Pharmacoeconomics Outcomes Res 5:153-162, 2005 45. Tumialán LM, Ponton RP, Gluf WM: Management of unilateral cervical radiculopathy in the military: the cost effectiveness of posterior cervical foraminotomy compared with anterior cervical discectomy and fusion. Neurosurg Focus 28:E17, 2010 46. Van den Akker ME, Arts MP, van den Hout WB, Brand R, Koes BW, Peul WC: Tubular Diskectomy vs Conventional Microdiskectomy for the Treatment of Lumbar Disk-Related Sciatica: Cost Utility Analysis Alongside a Double-Blind Randomized Controlled Trial. Neurosurgery 69:829–36, 2011 47. Van den Hout WB, Peul WC, Koes BW, Brand R, Kievit J, Thomeer RT, et al: Prolonged conservative care versus early surgery in patients with sciatica from lumbar disc herniation: cost utility analysis alongside a randomised controlled trial. BMJ 336:1351-4, 2008 48. Weinstein MC, Siegel JE, Gold MR, Kamlet MS, Russell LB: Recommendations of the Panel on Cost-effectiveness in Health and Medicine. JAMA 276:1253–8, 1996 49. Whitmore RG, Schwartz JS, Simmons S, Stein SC, Ghoawala Z: Performing a Cost Analysis in Spine Outcomes Research: Comparing Ventral and Dorsal Approaches for Cervical Spondylotic Myelopathy. Neurosurgery 70:860-67, 2012