SPINE Volume 39, Number 22S, pp S53-S64 ©2014, Lippincott Williams & Wilkins
ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS
Cervical Degenerative Disease Systematic Review of Economic Analyses Matthew D. Alvin, MBA, MA,*† Sheeraz Qureshi, MD, MBA,‡ Eric Klineberg, MD,§ K. Daniel Riew, MD,¶ Dena J. Fischer, DDS, MSD, MS, Daniel C. Norvell, PhD, MS, and Thomas E. Mroz, MD**
Study Design. Systematic review. Objective. To perform an evidence-based synthesis of the literature assessing the cost-effectiveness of surgery for patients with symptomatic cervical degenerative disc disease (DDD). Summary of Background Data. Cervical DDD is a common cause of clinical syndromes such as neck pain, cervical radiculopathy, and myelopathy. The appropriate surgical intervention(s) for a given problem is controversial, especially with regard to quality-of-life outcomes, complications, and costs. Although there have been many studies comparing outcomes and complications, relatively few have compared costs and, more importantly, cost-effectiveness of the interventions. Methods. We conducted a systematic search in PubMed/ MEDLINE, EMBASE, the Cochrane Collaboration Library, the CostEffectiveness Analysis registry database, and the National Health Service Economic Evaluation Database for full economic evaluations published through January 16, 2014. Identification of full economic evaluations that were explicitly designed to evaluate and synthesize the costs and consequences of surgical procedures or surgical intervention with nonsurgical management in patients with cervical DDD were considered for inclusion, based on 4 key questions.
From the *Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, OH; †Case Western Reserve University School of Medicine, Cleveland, OH; ‡Department of Orthopaedic Surgery, Mount Sinai Medical Center, New York, NY; §Department of Orthopedic Surgery, University of California Davis, Davis, CA;¶Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO; Spectrum Research Inc., Tacoma, WA; and **Departments of Orthopaedic and Neurological Surgery, Cleveland Clinic, Cleveland, OH. Acknowledgment date: April 14, 2014. First revision date: June 9, 2014. Second revision date: July 13, 2014. Acceptance date: July 27, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). Supported by AO Spine North America, Inc. Analytic support for this work was provided by Spectrum Research, Inc., with funding from the AO Spine North America. Relevant financial activities outside the submitted work: board membership, consultancy, grants, royalties, stocks, payment for lecture, expert testimony, travel/accommodations/meeting expenses. Address correspondence and reprint requests to Thomas E. Mroz, MD, Departments of Orthopaedic and Neurological Surgery, Neurological Institute, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave, S-80, Cleveland, OH 44195; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000547 Spine
Results. Five studies were included, each specific to 1 or more of our focus questions. Two studies suggested that cervical disc replacement may be more cost-effective compared with anterior cervical discectomy and fusion. Two studies comparing anterior with posterior surgical procedures for cervical spondylotic myelopathy suggested that anterior surgery was more cost-effective than posterior surgery. One study suggested that posterior cervical foraminotomy had a greater net economic benefit than anterior cervical discectomy and fusion in a military population with unilateral cervical radiculopathy. No studies assessed the cost-effectiveness of surgical intervention compared with nonoperative treatment of cervical myelopathy or radiculopathy, although it is acknowledged that existing studies demonstrate the cost-effectiveness of surgical intervention for these 2 clinical entities. Conclusion. A paucity of high-quality economic literature exists regarding cost-effectiveness of surgical intervention for cervical DDD. Future research is necessary to validate the findings of the few studies that do exist to guide decisions for surgery by the physician and patient with respect to cost-effectiveness. Key words: cervical spondylotic myelopathy, cervical degenerative disease, surgical intervention, cost-effectiveness, cost-benefit, ACDF, cervical disc arthroplasty, CDA, CDR, ICER. Level of Evidence: 2 Spine 2014;39:S53–S64
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ervical degenerative disc disease (DDD) can manifest as neck pain, cervical radiculopathy, and/or myelopathy. Although most can be managed nonoperatively, surgical intervention may be required for persistent or progressive symptoms. Currently, anterior cervical discectomy and fusion (ACDF) remains the most common surgical intervention for 1- or 2-level radiculopathy or myelopathy.1,2 Despite the proven long-term clinical and radiographical success of ACDF, enthusiasm has grown for nonfusion alternatives including posterior cervical foraminotomy (PCF) for radiculopathy, or cervical disc arthroplasty (CDR), laminectomy with fusion, and laminoplasty for radiculopathy or myelopathy.1,2 The major, but contentious, argument for motion preservation is that the latter surgical procedures will prevent, or lessen, the incidence of adjacent segment degeneration and disease compared with ACDF. Both CDR and PCF have been shown to produce equivalent, and in some cases superior, clinical www.spinejournal.com
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outcomes in patients with radiculopathy with the potential of avoiding the complications specific to ACDF (e.g., recurrent laryngeal nerve palsy, dysphagia, loss of range of motion, and adjacent segment disease).1–3 The same has been shown for laminoplasty versus ACDF for patients with myelopathy.4 Although comparisons on outcomes and complication rates among these procedures have been plentiful, comparisons on cost-effectiveness have been sparse. The primary goal of this review was to perform an evidence-based synthesis of the literature, assessing the costeffectiveness of surgical intervention for syndromes associated with cervical DDD. To accomplish this goal, we sought to answer the following key questions:
Critical Appraisal
1. Is there evidence to suggest that surgical intervention is cost-effective compared with nonoperative treatment of cervical myelopathy or radiculopathy? 2. Is there evidence to suggest that ACDF is cost-effective compared with CDR for cervical myelopathy or radiculopathy? 3. Is there evidence to suggest that anterior surgical procedures are cost-effective compared with posterior surgical procedures for cervical myelopathy? 4. Is there evidence to suggest that anterior surgical procedures are cost-effective compared with posterior surgical procedures for cervical radiculopathy?
The literature search yielded 250 unique, potentially relevant citations (Figure 1). Because the key questions were closely related, 1 literature search addressed all key questions. Two of the study authors (D.J.F., D.C.N.) independently considered studies for inclusion and discrepancies in selection were resolved by discussion. After title/abstract review, 228 articles were excluded, the majority of which did not assess the population or comparators of interest or were not economic studies. Among 22 full-text articles reviewed, 17 were excluded, the primary reason being that studies did not report the outcomes of interest. The details of the excluded studies are listed in the Supplemental Digital Content available at http://links.lww.com/BRS/A893. A total of 5 articles were retained that together addressed 3 of our 4 key questions (Tables 2, 3). Three cost-utility studies2,6,7 and 2 cost-effectiveness studies were included1,3. Additional detail about the included studies, including study limitations, is reported in Table 3 and the Supplemental Digital Content available at http://links.lww.com/BRS/A893.
MATERIALS AND METHODS General methods used for this systematic review are described in greater detail in the Supplemental Digital Content available at http://links.lww.com/BRS/A893 specific to this focus issue. Additional topic-specific methods are described below.
Electronic Literature Search We conducted a systematic search of PubMed/MEDLINE, EMBASE, the Cochrane Collaboration Library, the Tufts Cost-Effectiveness Analysis registry, and the National Health Service Economic Evaluation Database for full economic evaluations published through January 16, 2014 based on the key questions and Population, Intervention, Comparator, Outcomes inclusion/exclusion criteria established a priori (Table 1). The search strategy is further documented in the Supplemental Digital Content available at http://links.lww. com/BRS/A893. Only economic evaluations that evaluated and synthesized the costs and consequences of surgical procedures or surgical intervention with nonsurgical management in patients with cervical degenerative disease were considered for inclusion. Discrepancies were discussed so that consensus could be reached regarding final inclusion of studies.
Data Extraction and Analysis Data related to patient population characteristics, treatments, information on economic modeling parameters, and primary study findings, including those from sensitivity analyses, were abstracted (Supplemental Digital Content available at http:// links.lww.com/BRS/A893). Descriptive data and economic findings were reported as presented in the articles. S54
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The Quality of Health Economic Studies (QHES) instrument developed by Ofman et al5 was used to provide an initial basis for critical appraisal of the included economic studies and is described in the Materials and Methods section of this focus issue. Factors important in critical appraisal of studies from an epidemiological perspective were also considered. Two reviewers independently applied the QHES to the included studies. Discrepancies in ratings were discussed so that consensus could be reached and a final score obtained.
RESULTS Study Selection
KQ1: Is there evidence to suggest that surgical intervention is cost-effective compared with nonoperative treatment of cervical myelopathy or radiculopathy? No full economic evaluations existed relative to this question. KQ2: Is there evidence to suggest that ACDF is costeffective compared with CDR for cervical myelopathy or radiculopathy? Two economic evaluations compared the cost-effectiveness of ACDF with CDR for cervical myelopathy or radiculopathy (Tables 2, 3).1,2 Menzin et al1 performed a cost-benefit assessment (type of cost-effectiveness study), the focus of which was to evaluate the difference between incremental medical costs and gains in work productivity when comparing CDR with ACDF in patients with single-level disc disease and radiculopathy or myelopathy. In a randomized controlled trial, 541 patients were assigned to treatment with either CDR (n = 276) or ACDF (n = 265) and followed for 2 years. Electronic billing data available for a portion of the clinical trial population (n = 68; 12.6%) were used to determine inpatient facility costs. October 2014
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Cost-effectiveness of Surgery for Cervical DDD • Alvin et al
TABLE 1. Inclusion and Exclusion Criteria for Key Questions 1 to 4 Study Component
Inclusion
Exclusion
Population
Adults with cervical degenerative disease
Pediatric population ACDF)
∆ EQ-5D: ICER not 0.03 calculated, (anterior > anterior posterior) dominates
∆ QALY: 2.02 (CDR < ACDF)
∆ VWP: $6547 (CDR > ACDF)
Difference in Outcome
Primary Findings (e.g., ICER, Other) Range
(Continued )
No description of modeling used or model specifications Short-time horizon No sensitivity analysis Economic analysis conducted on a subset of patients (n = 41)
Only 1-way sensitivity analyses No complex modeling (e.g., Markov) Differential utility values for ACDF, CDR Differential hardware failure rates for ACDF, CDR
No description of modeling used or model specifications Short-time horizon Clinical trial was designed and powered around clinical endpoints rather than economic outcomes No sensitivity analysis Analysis limited to economic elements that were prospectively captured in the clinical trial (did not examine costs of other services, such as medication and physical therapy) Hospital bills for initial stay were available for only 12.6% of patients; no hospital bills available for secondary procedures
Primary Limitations
ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS Cost-effectiveness of Surgery for Cervical DDD • Alvin et al
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Country: United States Design: Costeffectiveness (utility) analysis Perspective: Hospitalbased and societybased Currency: 2010 US dollar
Currency: NR
1 yr
Anterior surgery Posterior surgery
Time Horizon Treatments
CCR method $21,563 (anterior) $27,942 (posterior) Medicare reimbursement method $17,538 (anterior) $16,569 (posterior) Outpatient costs
Costs
Country: United States Design: cost benefit Perspective: societal Currency: 2009 US dollar
NR
ACDF PCF
$10,078 (ACDF) $3570 (PCF)
$6508 (PCF < ACDF)
Time to return to duty 19.6 wk (ACDF) 4.8 wk (PCF)
No description of modeling used or model specifications Short-time horizon No sensitivity analysis Direct costs were derived from the index hospitalization only Outpatient costs were not included in ICER calculations
Economic analysis did not include postoperative care, productivity loss, or costs associated with subsequent hospitalizations
Primary Limitations
∆ Time: 14.8 net economic No description of modeling used wk (PCF < benefit: PCF or model specifications ACDF) > ACDF Short-time horizon No sensitivity analysis Bonus pay was not included in the cost estimation
∆ QALY: ICER not 0.03 calculated, (anterior > anterior posterior) dominates
Difference in Outcome
Primary Findings (e.g., ICER, Other) Range
NR indicates no report; ACDF, anterior cervical discectomy and fusion; CDR, cervical disc replacement; VWP, value of work productivity; EQ-5D, EuroQol-5D; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life year; PCF, posterior cervical foraminotomy; CCR, cost-to-charge ratio.
Tumialan et al3
Difference in Costs
Outcome (QALY, Utility, Clinical)
CCR method 0.16 QALYs (anterior) $6379 (anterior < 0.13 QALYs (posterior) posterior) Medicare reimbursement method $959 (anterior > posterior) Outpatient costs $2735 (anterior < posterior)
Cost-effectiveness of anterior vs. posterior procedures for cervical radiculopathy
Whitmore (2012)
Author, Date
Country Design Perspective Currency
TABLE 3. ( Continued )
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS The average time to return to unrestricted full duty was significantly less in the PCF group compared with ACDF group (PCF, 4.8 wk; ACDF, 19.6 wk; P < 0.0001). Eighteen of 19 patients who underwent ACDF returned to unrestricted full duty, whereas one returned to an administrative role (change from prior duties). In the PCF group, 18 of 19 patients returned to unrestricted full duty, and one was unable to return to full duty; the time to return to duty for this patient was excluded. Total direct costs (i.e., hospital and instrumentation costs) in a 1-year period were $6508 less for PCF compared with ACDF (PCF, $3570; ACDF, $10,078). Indirect costs for the ranks of junior enlisted service member (E4), senior enlisted member (E7), junior officer (O1), and senior officer (O4) were as follows: $13,586; $17,797; $17,475; and $24,045, respectively. The total cost (direct and indirect) differences between procedures for an E4, E7, O1, and O4 service member were $20,094, $24,305, $23,983, and $30,553, respectively. PCF had a greater net economic benefit than ACDF because PCF was less costly and resulted in a shorter time to return to unrestricted full duty.
DISCUSSION As the United States moves toward a value-based health care system, substantiation of treatments for various spinal conditions will become necessary. Value-based health care emphasizes identification of the optimal treatment option for a given pathology, where optimal is defined as the greatest gain in quality of life at the lowest cost. There have been few cost-effectiveness studies in the spine surgery literature, and even within the field, analyses of degenerative cervical conditions have been particularly neglected. In a literature review of all cost-utility analyses in spine care through 2010, Kepler et al8 identified 28 studies, of which only 4 (14%) involved the cervical spine. Similarly, the present review identified only 5 studies meeting the inclusion criteria. However, our goal in conducting this review was to identify what has been done and propose recommendations for future cost-effectiveness studies in this area. There is a high degree of heterogeneity among the published studies on this topic. The studies identified in the present review differ with regard to quality, how costs are calculated, what perspective was used (i.e., societal/hospital/payer), as well as the study design. Most studies did not report the explicit methodology for modeling, and it was unclear what assumptions were made and what was the justification for the economic model chosen. The follow-up periods were limited in duration, and may not adequately represent the longer term costs and clinical outcomes associated with these procedures. For example, only 1 study2 conducted a sensitivity analysis and had a follow-up of greater than 2 years and performed proper discounting of costs per the recommendations of the 1996 Panel on cost-effectiveness in Health and Medicine.9 Scores on QHES in the range from 34 to 70, suggesting variation in the extent to which studies met quality standards. Other limitations are discussed in Tables 2 and 3 and the Supplemental Digital Content available at http://links.lww.com/BRS/A893. Although we understand that there are certain clinical scenarios where a particular procedure is clearly the best S62
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choice, we are able to summarize what the included studies have shown. It must be recognized, however, that we think that each study had flaws in design that necessitate further research to validate the stated findings. First, CDR is more cost-effective than ACDF for patients with single-level cervical DDD and radiculopathy1,2 (Menzin et al1, 2 yr postsurgery; Qureshi et al, >10–11 yr postsurgery) or myelopathy (Menzin et al1, 2 yr postsurgery). Second, anterior surgery is more cost-effective than posterior surgery for patients with CSM at 1 year postsurgery.6,7 Finally, PCF is less costly than ACDF for patients with single-level cervical radiculopathy at 1-year postsurgery.3 Clearly, conclusions based on 1 or 2 studies need to be further validated by high-quality prospective investigations. For example, for anterior versus posterior surgery for CSM, studies commonly have different subsets of patients treated with anterior or posterior techniques. Specifically, anterior techniques are more commonly used in younger patients with more focal pathology, less neurological impairment, and less medical comorbidity. Conclusions on cost-effectiveness may be heavily influenced by patient demographics.10 In the study by Qureshi et al, the literature value assumptions for CDR and ACDF may not accurately represent true values. At the time of this study, health utility indices for patients with degenerative cervical spine conditions were not available, thus necessitating the need to make assumptions that affect the study findings. Since that time, Qureshi et al11 have published further literature defining health utility indices in the study population as well as long-term complications and their associated costs. Although the health utility indices and updated complication profile has been published, a repeat cost-effectiveness comparison is still lacking. The assumptions made by the authors regarding preoperative and postoperative health utility state and the lack of comprehensive cost analysis given the design of the study may have affected the value equation significantly. Further studies are necessary with the new information now available. There was insufficient evidence to address our first key question because there were no full economic evaluations comparing surgical with conservative management for myelopathy or radiculopathy. Indeed, studies have been conducted that show that surgery is cost-effective for both CSM (e.g., Fehlings et al12) and radiculopathy (e.g., Carreon et al13). However, these studies were excluded from the present review because they did not involve comparisons between either 2 surgical procedures or surgery versus nonoperative management. Fehlings et al12 conducted a retrospective review (n = 70) on patients undergoing surgery for CSM. During 10 years of follow-up, patients gained a total of 0.64 QALYs with an average cost of Can$21,066, producing a favorable cost-utility ratio. Relative to the comparison between operative and nonoperative management for CSM, relatively few studies have been conducted on the topic. In 2013, Rhee et al14 performed a systematic review of nonoperative management for CSM. The authors identified only 5 studies and concluded that nonoperative management may yield equivalent outcomes to surgery for patients with mild myelopathy, but beyond mild symptoms, nonoperative management is inferior to surgery. Although October 2014
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS future research may be helpful, it is unlikely to be undertaken because there is no longer therapeutic equipoise between operative and nonoperative approaches for CSM. Specially, Fehlings et al15 found that in the case of mild myelopathy, there is little evidence that nonoperative treatment may have a role; for moderate and severe myelopathy, nonoperative treatment results in outcomes inferior to those of surgery. The primary goal of this review was to identify whether evidence exists regarding the cost-effectiveness of surgical interventions in patients with cervical DDD. Three of the 4 key questions were addressed, albeit by only 1 or 2 studies. This is not ideal given the high incidence of surgery for cervical DDD and continuing evolution of health care in this country. The few studies included suggest that CDR may be more costeffective than ACDF for patients with cervical radiculopathy or myelopathy at 1-year follow-up, and that PCF may be more cost-effective than ACDF for radiculopathy at 2-year followup. However, the relatively low quality of evidence (low QHES scores) and the numerous study limitations necessitates further, more uniform, and longer follow-up analyses prior to making definitive conclusions and recommendations. These preliminary conclusions, however, do allow us to make several recommendations going forward. First, investigators wishing to conduct cost-effectiveness analyses on this topic should adopt a standardized cost-utility methodology for proper comparability and interpretation by policy makers and the public. This includes both comprehensive long-term follow-up costs and highly valid quality of life outcome questionnaire data. Second, these analyses should directly compare either 2 surgical interventions or surgical versus nonsurgical interventions using an ICER value and be specific about what indication patients are receiving treatment of (e.g., radiculopathy vs. myelopathy vs. neck pain alone). Third, other surgical interventions should be explored, including laminoplasty, anterior corpectomy, and hybrid approaches (i.e., combination ACDF/ corpectomy), and different models of cervical disc prosthesis used in CDR. Finally, longer term follow-up is necessary for cost-effectiveness studies to define important aspects such as adjacent level surgery, failure rates, and clinical outcomes.
CONCLUSION Cost-effectiveness analyses on surgical interventions for cervical DDD are lacking in the literature. Future research is necessary to validate the findings of the few analyses that do exist and to examine surgery versus nonoperative management in particular. Investigators seeking to perform such analyses should be transparent in their methodology and cost calculations with an ICER as the endpoint to properly compare interventions.
➢ Key Points Common surgical interventions for cervical spondylosis include ACDF, posterior foraminotomy, and CDR.
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Cost-effectiveness of Surgery for Cervical DDD • Alvin et al
Although many studies have been done comparing outcomes and complication rates between interventions, few have focused on costs or costeffectiveness. In those studies that do focus on cost-effectiveness, CDR, ventral fusion, and foraminotomy are more cost-effective than ACDF, dorsal fusion, and ACDF, respectively. Future research is necessary to validate the findings of the few studies that do exist.
Acknowledgements The authors thank Nancy Holmes and Ms Chi Lam for their administrative assistance. Supplemental digital content is available for this article. Direct URL citations appearing in the printed text are provided in the HTML and PDF version of this article on the journal’s web site (www.spinejournal.com).
References
1. Menzin J, Zhang B, Zeumann PJ, et al. A health-economic assessment of cervical disc arthroplasty compared with allograft fusion. Tech Orthop 2010;25:133–7. 2. Qureshi SA, McAnany S, Goz V, et al. Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion: clinical article. J Neurosurg Spine 2013;19:546–54. 3. Tumialan 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 2010; 28:E17. 4. Liu T, Yang HL, Xu YZ, et al. ACDF with the PCB cageplate system versus laminoplasty for multilevel cervical spondylotic myelopathy. J Spinal Disord Tech 2011;24: 213–20. 5. Ofman JJ, Sullivan SD, Neumann PJ, et al. Examining the value and quality of health economic analyses: implications of utilizing the QHES. JMCP 2003;9:53–61. 6. Ghogawala Z, Martin B, Benzel EC, et al. Comparative effectiveness of ventral vs. dorsal surgery for cervical spondylotic myelopathy. Neurosurgery 2011;68:622–30; discussion 30–1. 7. Whitmore RG, Schwartz JS, Simmons S, et al. Performing a cost analysis in spine outcomes research: comparing ventral and dorsal approaches for cervical spondylotic myelopathy. Neurosurgery 2012;70:860–7; discussion 7. 8. Kepler CK, Wilkinson SM, Radcliff KE, et al. Cost-utility analysis in spine care: a systematic review. Spine J 2012;12: 676–90. 9. Weinstein MC, Siegel JE, Gold MR, et al. Recommendations of the Panel on Cost-effectiveness in Health and Medicine. JAMA 1996;276:1253–8. 10. Fehlings MG, Barry S, Kopjar B, et al. Anterior versus posterior surgical approaches to treat cervical spondylotic myelopathy: outcomes of the prospective multicenter AOSpine North America CSM study in 264 patients. Spine (Phila Pa 1976) 2013;38: 2247–52. 11. Qureshi S, Goz V, McAnany S, et al. Health state utility of patients with single-level cervical degenerative disc disease: comparison of anterior cervical discectomy and fusion with cervical disc arthroplasty. J Neurosurg Spine 2014;20:475–9. www.spinejournal.com
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS 12. Fehlings MG, Jha NK, Hewson SM, et al. 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 2012;17:89–93. 13. Carreon LY, Anderson PA, Traynelis VC, et al. Cost-effectiveness of single-level anterior cervical discectomy and fusion five years after surgery. Spine (Phila Pa 1976) 2013;38:471–5.
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14. Rhee JM, Shamji MF, Erwin WM, et al. Nonoperative management of cervical myelopathy: a systematic review. Spine (Phila Pa 1976) 2013;38:S55–67. 15. Fehlings MG, Wilson JR, Yoon ST, et al. Symptomatic progression of cervical myelopathy and the role of nonsurgical management: a consensus statement. Spine (Phila Pa 1976) 2013;38: S19–20.
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Cervical Degenerative Disease Systematic Review of Economic Analyses Matthew D. Alvin, MBA, MA,*† Sheeraz Qureshi, MD, MBA,‡ Eric Klineberg, MD,§ K. Daniel Riew, MD,¶ Dena J. Fischer, DDS, MSD, MS, Daniel C. Norvell, PhD, MS, and Thomas E. Mroz, MD**
Study Design. Systematic review. Objective. To perform an evidence-based synthesis of the literature assessing the cost-effectiveness of surgery for patients with symptomatic cervical degenerative disc disease (DDD). Summary of Background Data. Cervical DDD is a common cause of clinical syndromes such as neck pain, cervical radiculopathy, and myelopathy. The appropriate surgical intervention(s) for a given problem is controversial, especially with regard to quality-of-life outcomes, complications, and costs. Although there have been many studies comparing outcomes and complications, relatively few have compared costs and, more importantly, cost-effectiveness of the interventions. Methods. We conducted a systematic search in PubMed/ MEDLINE, EMBASE, the Cochrane Collaboration Library, the CostEffectiveness Analysis registry database, and the National Health Service Economic Evaluation Database for full economic evaluations published through January 16, 2014. Identification of full economic evaluations that were explicitly designed to evaluate and synthesize the costs and consequences of surgical procedures or surgical intervention with nonsurgical management in patients with cervical DDD were considered for inclusion, based on 4 key questions.
From the *Cleveland Clinic Center for Spine Health, Cleveland Clinic, Cleveland, OH; †Case Western Reserve University School of Medicine, Cleveland, OH; ‡Department of Orthopaedic Surgery, Mount Sinai Medical Center, New York, NY; §Department of Orthopedic Surgery, University of California Davis, Davis, CA;¶Department of Orthopaedic Surgery, Washington University School of Medicine, St Louis, MO; Spectrum Research Inc., Tacoma, WA; and **Departments of Orthopaedic and Neurological Surgery, Cleveland Clinic, Cleveland, OH. Acknowledgment date: April 14, 2014. First revision date: June 9, 2014. Second revision date: July 13, 2014. Acceptance date: July 27, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). Supported by AO Spine North America, Inc. Analytic support for this work was provided by Spectrum Research, Inc., with funding from the AO Spine North America. Relevant financial activities outside the submitted work: board membership, consultancy, grants, royalties, stocks, payment for lecture, expert testimony, travel/accommodations/meeting expenses. Address correspondence and reprint requests to Thomas E. Mroz, MD, Departments of Orthopaedic and Neurological Surgery, Neurological Institute, Cleveland Clinic Center for Spine Health, The Cleveland Clinic, 9500 Euclid Ave, S-80, Cleveland, OH 44195; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000547 Spine
Results. Five studies were included, each specific to 1 or more of our focus questions. Two studies suggested that cervical disc replacement may be more cost-effective compared with anterior cervical discectomy and fusion. Two studies comparing anterior with posterior surgical procedures for cervical spondylotic myelopathy suggested that anterior surgery was more cost-effective than posterior surgery. One study suggested that posterior cervical foraminotomy had a greater net economic benefit than anterior cervical discectomy and fusion in a military population with unilateral cervical radiculopathy. No studies assessed the cost-effectiveness of surgical intervention compared with nonoperative treatment of cervical myelopathy or radiculopathy, although it is acknowledged that existing studies demonstrate the cost-effectiveness of surgical intervention for these 2 clinical entities. Conclusion. A paucity of high-quality economic literature exists regarding cost-effectiveness of surgical intervention for cervical DDD. Future research is necessary to validate the findings of the few studies that do exist to guide decisions for surgery by the physician and patient with respect to cost-effectiveness. Key words: cervical spondylotic myelopathy, cervical degenerative disease, surgical intervention, cost-effectiveness, cost-benefit, ACDF, cervical disc arthroplasty, CDA, CDR, ICER. Level of Evidence: 2 Spine 2014;39:S53–S64
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ervical degenerative disc disease (DDD) can manifest as neck pain, cervical radiculopathy, and/or myelopathy. Although most can be managed nonoperatively, surgical intervention may be required for persistent or progressive symptoms. Currently, anterior cervical discectomy and fusion (ACDF) remains the most common surgical intervention for 1- or 2-level radiculopathy or myelopathy.1,2 Despite the proven long-term clinical and radiographical success of ACDF, enthusiasm has grown for nonfusion alternatives including posterior cervical foraminotomy (PCF) for radiculopathy, or cervical disc arthroplasty (CDR), laminectomy with fusion, and laminoplasty for radiculopathy or myelopathy.1,2 The major, but contentious, argument for motion preservation is that the latter surgical procedures will prevent, or lessen, the incidence of adjacent segment degeneration and disease compared with ACDF. Both CDR and PCF have been shown to produce equivalent, and in some cases superior, clinical www.spinejournal.com
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outcomes in patients with radiculopathy with the potential of avoiding the complications specific to ACDF (e.g., recurrent laryngeal nerve palsy, dysphagia, loss of range of motion, and adjacent segment disease).1–3 The same has been shown for laminoplasty versus ACDF for patients with myelopathy.4 Although comparisons on outcomes and complication rates among these procedures have been plentiful, comparisons on cost-effectiveness have been sparse. The primary goal of this review was to perform an evidence-based synthesis of the literature, assessing the costeffectiveness of surgical intervention for syndromes associated with cervical DDD. To accomplish this goal, we sought to answer the following key questions:
Critical Appraisal
1. Is there evidence to suggest that surgical intervention is cost-effective compared with nonoperative treatment of cervical myelopathy or radiculopathy? 2. Is there evidence to suggest that ACDF is cost-effective compared with CDR for cervical myelopathy or radiculopathy? 3. Is there evidence to suggest that anterior surgical procedures are cost-effective compared with posterior surgical procedures for cervical myelopathy? 4. Is there evidence to suggest that anterior surgical procedures are cost-effective compared with posterior surgical procedures for cervical radiculopathy?
The literature search yielded 250 unique, potentially relevant citations (Figure 1). Because the key questions were closely related, 1 literature search addressed all key questions. Two of the study authors (D.J.F., D.C.N.) independently considered studies for inclusion and discrepancies in selection were resolved by discussion. After title/abstract review, 228 articles were excluded, the majority of which did not assess the population or comparators of interest or were not economic studies. Among 22 full-text articles reviewed, 17 were excluded, the primary reason being that studies did not report the outcomes of interest. The details of the excluded studies are listed in the Supplemental Digital Content available at http://links.lww.com/BRS/A893. A total of 5 articles were retained that together addressed 3 of our 4 key questions (Tables 2, 3). Three cost-utility studies2,6,7 and 2 cost-effectiveness studies were included1,3. Additional detail about the included studies, including study limitations, is reported in Table 3 and the Supplemental Digital Content available at http://links.lww.com/BRS/A893.
MATERIALS AND METHODS General methods used for this systematic review are described in greater detail in the Supplemental Digital Content available at http://links.lww.com/BRS/A893 specific to this focus issue. Additional topic-specific methods are described below.
Electronic Literature Search We conducted a systematic search of PubMed/MEDLINE, EMBASE, the Cochrane Collaboration Library, the Tufts Cost-Effectiveness Analysis registry, and the National Health Service Economic Evaluation Database for full economic evaluations published through January 16, 2014 based on the key questions and Population, Intervention, Comparator, Outcomes inclusion/exclusion criteria established a priori (Table 1). The search strategy is further documented in the Supplemental Digital Content available at http://links.lww. com/BRS/A893. Only economic evaluations that evaluated and synthesized the costs and consequences of surgical procedures or surgical intervention with nonsurgical management in patients with cervical degenerative disease were considered for inclusion. Discrepancies were discussed so that consensus could be reached regarding final inclusion of studies.
Data Extraction and Analysis Data related to patient population characteristics, treatments, information on economic modeling parameters, and primary study findings, including those from sensitivity analyses, were abstracted (Supplemental Digital Content available at http:// links.lww.com/BRS/A893). Descriptive data and economic findings were reported as presented in the articles. S54
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The Quality of Health Economic Studies (QHES) instrument developed by Ofman et al5 was used to provide an initial basis for critical appraisal of the included economic studies and is described in the Materials and Methods section of this focus issue. Factors important in critical appraisal of studies from an epidemiological perspective were also considered. Two reviewers independently applied the QHES to the included studies. Discrepancies in ratings were discussed so that consensus could be reached and a final score obtained.
RESULTS Study Selection
KQ1: Is there evidence to suggest that surgical intervention is cost-effective compared with nonoperative treatment of cervical myelopathy or radiculopathy? No full economic evaluations existed relative to this question. KQ2: Is there evidence to suggest that ACDF is costeffective compared with CDR for cervical myelopathy or radiculopathy? Two economic evaluations compared the cost-effectiveness of ACDF with CDR for cervical myelopathy or radiculopathy (Tables 2, 3).1,2 Menzin et al1 performed a cost-benefit assessment (type of cost-effectiveness study), the focus of which was to evaluate the difference between incremental medical costs and gains in work productivity when comparing CDR with ACDF in patients with single-level disc disease and radiculopathy or myelopathy. In a randomized controlled trial, 541 patients were assigned to treatment with either CDR (n = 276) or ACDF (n = 265) and followed for 2 years. Electronic billing data available for a portion of the clinical trial population (n = 68; 12.6%) were used to determine inpatient facility costs. October 2014
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Cost-effectiveness of Surgery for Cervical DDD • Alvin et al
TABLE 1. Inclusion and Exclusion Criteria for Key Questions 1 to 4 Study Component
Inclusion
Exclusion
Population
Adults with cervical degenerative disease
Pediatric population ACDF)
∆ EQ-5D: ICER not 0.03 calculated, (anterior > anterior posterior) dominates
∆ QALY: 2.02 (CDR < ACDF)
∆ VWP: $6547 (CDR > ACDF)
Difference in Outcome
Primary Findings (e.g., ICER, Other) Range
(Continued )
No description of modeling used or model specifications Short-time horizon No sensitivity analysis Economic analysis conducted on a subset of patients (n = 41)
Only 1-way sensitivity analyses No complex modeling (e.g., Markov) Differential utility values for ACDF, CDR Differential hardware failure rates for ACDF, CDR
No description of modeling used or model specifications Short-time horizon Clinical trial was designed and powered around clinical endpoints rather than economic outcomes No sensitivity analysis Analysis limited to economic elements that were prospectively captured in the clinical trial (did not examine costs of other services, such as medication and physical therapy) Hospital bills for initial stay were available for only 12.6% of patients; no hospital bills available for secondary procedures
Primary Limitations
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Country: United States Design: Costeffectiveness (utility) analysis Perspective: Hospitalbased and societybased Currency: 2010 US dollar
Currency: NR
1 yr
Anterior surgery Posterior surgery
Time Horizon Treatments
CCR method $21,563 (anterior) $27,942 (posterior) Medicare reimbursement method $17,538 (anterior) $16,569 (posterior) Outpatient costs
Costs
Country: United States Design: cost benefit Perspective: societal Currency: 2009 US dollar
NR
ACDF PCF
$10,078 (ACDF) $3570 (PCF)
$6508 (PCF < ACDF)
Time to return to duty 19.6 wk (ACDF) 4.8 wk (PCF)
No description of modeling used or model specifications Short-time horizon No sensitivity analysis Direct costs were derived from the index hospitalization only Outpatient costs were not included in ICER calculations
Economic analysis did not include postoperative care, productivity loss, or costs associated with subsequent hospitalizations
Primary Limitations
∆ Time: 14.8 net economic No description of modeling used wk (PCF < benefit: PCF or model specifications ACDF) > ACDF Short-time horizon No sensitivity analysis Bonus pay was not included in the cost estimation
∆ QALY: ICER not 0.03 calculated, (anterior > anterior posterior) dominates
Difference in Outcome
Primary Findings (e.g., ICER, Other) Range
NR indicates no report; ACDF, anterior cervical discectomy and fusion; CDR, cervical disc replacement; VWP, value of work productivity; EQ-5D, EuroQol-5D; ICER, incremental cost-effectiveness ratio; QALY, quality-adjusted life year; PCF, posterior cervical foraminotomy; CCR, cost-to-charge ratio.
Tumialan et al3
Difference in Costs
Outcome (QALY, Utility, Clinical)
CCR method 0.16 QALYs (anterior) $6379 (anterior < 0.13 QALYs (posterior) posterior) Medicare reimbursement method $959 (anterior > posterior) Outpatient costs $2735 (anterior < posterior)
Cost-effectiveness of anterior vs. posterior procedures for cervical radiculopathy
Whitmore (2012)
Author, Date
Country Design Perspective Currency
TABLE 3. ( Continued )
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS The average time to return to unrestricted full duty was significantly less in the PCF group compared with ACDF group (PCF, 4.8 wk; ACDF, 19.6 wk; P < 0.0001). Eighteen of 19 patients who underwent ACDF returned to unrestricted full duty, whereas one returned to an administrative role (change from prior duties). In the PCF group, 18 of 19 patients returned to unrestricted full duty, and one was unable to return to full duty; the time to return to duty for this patient was excluded. Total direct costs (i.e., hospital and instrumentation costs) in a 1-year period were $6508 less for PCF compared with ACDF (PCF, $3570; ACDF, $10,078). Indirect costs for the ranks of junior enlisted service member (E4), senior enlisted member (E7), junior officer (O1), and senior officer (O4) were as follows: $13,586; $17,797; $17,475; and $24,045, respectively. The total cost (direct and indirect) differences between procedures for an E4, E7, O1, and O4 service member were $20,094, $24,305, $23,983, and $30,553, respectively. PCF had a greater net economic benefit than ACDF because PCF was less costly and resulted in a shorter time to return to unrestricted full duty.
DISCUSSION As the United States moves toward a value-based health care system, substantiation of treatments for various spinal conditions will become necessary. Value-based health care emphasizes identification of the optimal treatment option for a given pathology, where optimal is defined as the greatest gain in quality of life at the lowest cost. There have been few cost-effectiveness studies in the spine surgery literature, and even within the field, analyses of degenerative cervical conditions have been particularly neglected. In a literature review of all cost-utility analyses in spine care through 2010, Kepler et al8 identified 28 studies, of which only 4 (14%) involved the cervical spine. Similarly, the present review identified only 5 studies meeting the inclusion criteria. However, our goal in conducting this review was to identify what has been done and propose recommendations for future cost-effectiveness studies in this area. There is a high degree of heterogeneity among the published studies on this topic. The studies identified in the present review differ with regard to quality, how costs are calculated, what perspective was used (i.e., societal/hospital/payer), as well as the study design. Most studies did not report the explicit methodology for modeling, and it was unclear what assumptions were made and what was the justification for the economic model chosen. The follow-up periods were limited in duration, and may not adequately represent the longer term costs and clinical outcomes associated with these procedures. For example, only 1 study2 conducted a sensitivity analysis and had a follow-up of greater than 2 years and performed proper discounting of costs per the recommendations of the 1996 Panel on cost-effectiveness in Health and Medicine.9 Scores on QHES in the range from 34 to 70, suggesting variation in the extent to which studies met quality standards. Other limitations are discussed in Tables 2 and 3 and the Supplemental Digital Content available at http://links.lww.com/BRS/A893. Although we understand that there are certain clinical scenarios where a particular procedure is clearly the best S62
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choice, we are able to summarize what the included studies have shown. It must be recognized, however, that we think that each study had flaws in design that necessitate further research to validate the stated findings. First, CDR is more cost-effective than ACDF for patients with single-level cervical DDD and radiculopathy1,2 (Menzin et al1, 2 yr postsurgery; Qureshi et al, >10–11 yr postsurgery) or myelopathy (Menzin et al1, 2 yr postsurgery). Second, anterior surgery is more cost-effective than posterior surgery for patients with CSM at 1 year postsurgery.6,7 Finally, PCF is less costly than ACDF for patients with single-level cervical radiculopathy at 1-year postsurgery.3 Clearly, conclusions based on 1 or 2 studies need to be further validated by high-quality prospective investigations. For example, for anterior versus posterior surgery for CSM, studies commonly have different subsets of patients treated with anterior or posterior techniques. Specifically, anterior techniques are more commonly used in younger patients with more focal pathology, less neurological impairment, and less medical comorbidity. Conclusions on cost-effectiveness may be heavily influenced by patient demographics.10 In the study by Qureshi et al, the literature value assumptions for CDR and ACDF may not accurately represent true values. At the time of this study, health utility indices for patients with degenerative cervical spine conditions were not available, thus necessitating the need to make assumptions that affect the study findings. Since that time, Qureshi et al11 have published further literature defining health utility indices in the study population as well as long-term complications and their associated costs. Although the health utility indices and updated complication profile has been published, a repeat cost-effectiveness comparison is still lacking. The assumptions made by the authors regarding preoperative and postoperative health utility state and the lack of comprehensive cost analysis given the design of the study may have affected the value equation significantly. Further studies are necessary with the new information now available. There was insufficient evidence to address our first key question because there were no full economic evaluations comparing surgical with conservative management for myelopathy or radiculopathy. Indeed, studies have been conducted that show that surgery is cost-effective for both CSM (e.g., Fehlings et al12) and radiculopathy (e.g., Carreon et al13). However, these studies were excluded from the present review because they did not involve comparisons between either 2 surgical procedures or surgery versus nonoperative management. Fehlings et al12 conducted a retrospective review (n = 70) on patients undergoing surgery for CSM. During 10 years of follow-up, patients gained a total of 0.64 QALYs with an average cost of Can$21,066, producing a favorable cost-utility ratio. Relative to the comparison between operative and nonoperative management for CSM, relatively few studies have been conducted on the topic. In 2013, Rhee et al14 performed a systematic review of nonoperative management for CSM. The authors identified only 5 studies and concluded that nonoperative management may yield equivalent outcomes to surgery for patients with mild myelopathy, but beyond mild symptoms, nonoperative management is inferior to surgery. Although October 2014
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS future research may be helpful, it is unlikely to be undertaken because there is no longer therapeutic equipoise between operative and nonoperative approaches for CSM. Specially, Fehlings et al15 found that in the case of mild myelopathy, there is little evidence that nonoperative treatment may have a role; for moderate and severe myelopathy, nonoperative treatment results in outcomes inferior to those of surgery. The primary goal of this review was to identify whether evidence exists regarding the cost-effectiveness of surgical interventions in patients with cervical DDD. Three of the 4 key questions were addressed, albeit by only 1 or 2 studies. This is not ideal given the high incidence of surgery for cervical DDD and continuing evolution of health care in this country. The few studies included suggest that CDR may be more costeffective than ACDF for patients with cervical radiculopathy or myelopathy at 1-year follow-up, and that PCF may be more cost-effective than ACDF for radiculopathy at 2-year followup. However, the relatively low quality of evidence (low QHES scores) and the numerous study limitations necessitates further, more uniform, and longer follow-up analyses prior to making definitive conclusions and recommendations. These preliminary conclusions, however, do allow us to make several recommendations going forward. First, investigators wishing to conduct cost-effectiveness analyses on this topic should adopt a standardized cost-utility methodology for proper comparability and interpretation by policy makers and the public. This includes both comprehensive long-term follow-up costs and highly valid quality of life outcome questionnaire data. Second, these analyses should directly compare either 2 surgical interventions or surgical versus nonsurgical interventions using an ICER value and be specific about what indication patients are receiving treatment of (e.g., radiculopathy vs. myelopathy vs. neck pain alone). Third, other surgical interventions should be explored, including laminoplasty, anterior corpectomy, and hybrid approaches (i.e., combination ACDF/ corpectomy), and different models of cervical disc prosthesis used in CDR. Finally, longer term follow-up is necessary for cost-effectiveness studies to define important aspects such as adjacent level surgery, failure rates, and clinical outcomes.
CONCLUSION Cost-effectiveness analyses on surgical interventions for cervical DDD are lacking in the literature. Future research is necessary to validate the findings of the few analyses that do exist and to examine surgery versus nonoperative management in particular. Investigators seeking to perform such analyses should be transparent in their methodology and cost calculations with an ICER as the endpoint to properly compare interventions.
➢ Key Points Common surgical interventions for cervical spondylosis include ACDF, posterior foraminotomy, and CDR.
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Cost-effectiveness of Surgery for Cervical DDD • Alvin et al
Although many studies have been done comparing outcomes and complication rates between interventions, few have focused on costs or costeffectiveness. In those studies that do focus on cost-effectiveness, CDR, ventral fusion, and foraminotomy are more cost-effective than ACDF, dorsal fusion, and ACDF, respectively. Future research is necessary to validate the findings of the few studies that do exist.
Acknowledgements The authors thank Nancy Holmes and Ms Chi Lam for their administrative assistance. Supplemental digital content is available for this article. Direct URL citations appearing in the printed text are provided in the HTML and PDF version of this article on the journal’s web site (www.spinejournal.com).
References
1. Menzin J, Zhang B, Zeumann PJ, et al. A health-economic assessment of cervical disc arthroplasty compared with allograft fusion. Tech Orthop 2010;25:133–7. 2. Qureshi SA, McAnany S, Goz V, et al. Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion: clinical article. J Neurosurg Spine 2013;19:546–54. 3. Tumialan 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 2010; 28:E17. 4. Liu T, Yang HL, Xu YZ, et al. ACDF with the PCB cageplate system versus laminoplasty for multilevel cervical spondylotic myelopathy. J Spinal Disord Tech 2011;24: 213–20. 5. Ofman JJ, Sullivan SD, Neumann PJ, et al. Examining the value and quality of health economic analyses: implications of utilizing the QHES. JMCP 2003;9:53–61. 6. Ghogawala Z, Martin B, Benzel EC, et al. Comparative effectiveness of ventral vs. dorsal surgery for cervical spondylotic myelopathy. Neurosurgery 2011;68:622–30; discussion 30–1. 7. Whitmore RG, Schwartz JS, Simmons S, et al. Performing a cost analysis in spine outcomes research: comparing ventral and dorsal approaches for cervical spondylotic myelopathy. Neurosurgery 2012;70:860–7; discussion 7. 8. Kepler CK, Wilkinson SM, Radcliff KE, et al. Cost-utility analysis in spine care: a systematic review. Spine J 2012;12: 676–90. 9. Weinstein MC, Siegel JE, Gold MR, et al. Recommendations of the Panel on Cost-effectiveness in Health and Medicine. JAMA 1996;276:1253–8. 10. Fehlings MG, Barry S, Kopjar B, et al. Anterior versus posterior surgical approaches to treat cervical spondylotic myelopathy: outcomes of the prospective multicenter AOSpine North America CSM study in 264 patients. Spine (Phila Pa 1976) 2013;38: 2247–52. 11. Qureshi S, Goz V, McAnany S, et al. Health state utility of patients with single-level cervical degenerative disc disease: comparison of anterior cervical discectomy and fusion with cervical disc arthroplasty. J Neurosurg Spine 2014;20:475–9. www.spinejournal.com
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ASSESSING VALUE OF SPECIFIC SPINE CONDITIONS 12. Fehlings MG, Jha NK, Hewson SM, et al. 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 2012;17:89–93. 13. Carreon LY, Anderson PA, Traynelis VC, et al. Cost-effectiveness of single-level anterior cervical discectomy and fusion five years after surgery. Spine (Phila Pa 1976) 2013;38:471–5.
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14. Rhee JM, Shamji MF, Erwin WM, et al. Nonoperative management of cervical myelopathy: a systematic review. Spine (Phila Pa 1976) 2013;38:S55–67. 15. Fehlings MG, Wilson JR, Yoon ST, et al. Symptomatic progression of cervical myelopathy and the role of nonsurgical management: a consensus statement. Spine (Phila Pa 1976) 2013;38: S19–20.
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