Is surgery for cervical spondylotic myelopathy cost-effective? A cost-utility analysis based on data from the AOSpine North America prospective CSM study

Cost-effectiveness of surgery for degenerative cervical myelopathy in the United Kingdom

PURPOSE

Degenerative cervical myelopathy (DCM) is the commonest cause of adult spinal cord dysfunction worldwide, for which surgery is the mainstay of treatment. At present, there is limited literature on the costs associated with the surgical management of DCM, and none from the United Kingdom (UK). This study aimed to evaluate the cost-effectiveness of DCM surgery within the National Health Service, UK.

MATERIALS AND METHODS

Incidence of DCM was identified from the Hospital Episode Statistics (HES) database for a single year using five ICD-10 diagnostic codes to represent DCM. Health Resource Group (HRG) data was used to estimate the mean incremental surgery (treatment) costs compared to non-surgical care, and the incremental effect (quality adjusted life year (QALY) gain) was based on data from a previous study. A cost per QALY value of <£30,000/QALY (GBP) was considered acceptable and cost-effective, as per the National Institute for Health and Clinical Excellence (NICE) guidance. A sensitivity analysis was undertaken (±5%, ±10% and ±20%) to account for variance in both the cost of admission and QALY gain.

RESULTS

The total number of admissions for DCM in 2018 was 4,218. Mean age was 62 years, with 54% of admissions being of working age (18-65 years). The overall estimated cost of admissions for DCM was £38,871,534 for the year. The mean incremental (per patient) cost of surgical management of DCM was estimated to be £9,216 (ranged £2,358 to £9,304), with a QALY gain of 0.64, giving an estimated cost per QALY value of £14,399/QALY. Varying the QALY gain by ±20%, resulted in cost/QALY figures between £12,000 (+20%) and £17,999 (-20%).

CONCLUSIONS

Surgery is estimated to be a cost-effective treatment of DCM amongst the UK population.

Trends in Indications and Contraindications for Cervical Disk Arthroplasty from 2009 to 2019

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

Assess trends of indications and contraindications for the use of Cervical Disk Arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

As spine surgeons become more familiar with CDA, there have been expansions in indications.

METHODS

The Medicare Provider Analysis and Review Limited Data Sets for 2009, 2014, and 2019 were utilized. Patients undergoing elective CDA were included. Diagnosis for index surgery and "contraindications" as defined by original CDA Investigative Device Exemption (IDE) criteria were assessed. Variables were identified by the International Classification of Diseases (ICD)-9 or ICD-10 diagnosis and procedural codes.

RESULTS

A total of 1067 elective CDA patients were included. There were 230 patients in 2009, 300 patients in 2014, and 537 patients in 2019. The proportion of patients aged >65 increased from 35% to 51% (P<0.001). Incidence of CDA for radiculopathy increased from 57% to 69% (P<0.001), myelopathy increased from 23% to 78% (P<0.001), and spondylosis without radiculopathy or myelopathy decreased from 19% to 3% (P<0.001). There were increased incidences of ankylosing spondylitis (0.4% to 2.8%, P=0.007), long-term steroid use (1% to 2%, P=0.039), morbid obesity (2% to 6%, P=0.019), and osteoporosis (1% to 5%, P=0.014). The incidence of hybrid CDA and anterior cervical discectomy and fusion (ACDF) decreased from 28% to 23% (P=0.007).

CONCLUSION

From 2009 to 2019, the number of CDA performed in older patients increased. An increase in the use of CDA for the treatment of myelopathy and radiculopathy and a decrease in the treatment of isolated cervical spondylosis was observed. The proportion of CDA performed in patients with original IDE trial "contraindications" increased. Further research into the efficacy of CDA for patients with contraindications is warranted.

Early surgery compared to nonoperative management for mild degenerative cervical myelopathy: a cost-utility analysis

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) is a form of acquired spinal cord compression and contributes to reduced quality of life secondary to neurological dysfunction and pain. There remains uncertainty regarding optimal management for individuals with mild myelopathy. Specifically, owing to lacking long-term natural history studies in this population, we do not know whether these individuals should be treated with initial surgery or observation.

PURPOSE

We sought to perform a cost-utility analysis to examine early surgery for mild degenerative cervical myelopathy from the healthcare payer perspective.

STUDY DESIGN/SETTING

We utilized data from the prospective observational cohorts included in the Cervical Spondylotic Myelopathy AO Spine International and North America studies to determine health related quality of life estimates and clinical myelopathy outcomes.

PATIENT SAMPLE

We recruited all patients that underwent surgery for DCM enrolled in the Cervical Spondylotic Myelopathy AO Spine International and North America studies between December 2005 and January 2011.

OUTCOME MEASURES

Clinical assessment measures were obtained using the Modified Japanese Orthopedic Association scale and health-related quality of life measures were obtained using the Short Form-6D utility score at baseline (preoperative), 6 months, 12 months and 24 months postsurgery. Cost measures inflated to January 2015 values were obtained using pooled estimates from the hospital payer perspective for surgical patients.

METHODS

We employed a Markov state transition model with Monte Carlo microsimulation using a lifetime horizon to obtain an incremental cost utility ratio associated with early surgery for mild myelopathy. Parameter uncertainty was assessed through deterministic means using one-way and two-way sensitivity analyses and probabilistically using parameter estimate distributions with microsimulation (10,000 trials). Costs and utilities were discounted at 3% per annum.

RESULTS

Initial surgery for mild degenerative cervical myelopathy was associated with an incremental lifetime increase of 1.26 quality-adjusted life years (QALY) compared to observation. The associated cost incurred to the healthcare payer over a lifetime horizon was $12,894.56, resulting in a lifetime incremental cost-utility ratio of $10,250.71/QALY. Utilizing a willingness to pay threshold in keeping with the World Health Organization definition of "very cost-effective" ($54,000 CDN), the probabilistic sensitivity analysis demonstrated that 100% of cases were cost-effective.

CONCLUSIONS

Surgery compared to initial observation for mild degenerative cervical myelopathy was cost-effective from the Canadian healthcare payer perspective and was associated with lifetime gains in health-related quality of life.

Validating the preoperative Japanese Core Outcome Measures Index for the Neck and comparing quality of life in patients with cervical spondylotic myelopathy and ossification of the posterior longitudinal ligament by the patient-reported outcome measures

PURPOSE

This cross-sectional study serves two main purposes. Firstly, it aims to validate the preoperative Japanese Core Outcome Measures Index for the Neck (COMI-Neck) in patients with cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Secondly, it seeks to elucidate differences in preoperative quality of life (QOL) between these two cervical pathologies using patient-reported outcome measures (PROMs).

METHODS

A total of 103 preoperative patients (86 with CSM and 17 with OPLL) scheduled for cervical spine surgery were included in the study. Validated PROMs, including the Japanese COMI-Neck, Neck Disability Index (NDI), EuroQol-5 Dimension-3 level (EQ-5D-3L), and SF-12v2, were used to assess QOL. Baseline demographic and clinical data were collected, and statistical analyses were performed to compare the PROMs between CSM and OPLL groups.

RESULTS

The Japanese COMI-Neck demonstrated good construct validity, with positive correlations with NDI and negative correlations with EQ-5D-3L and SF-12v2. Comparison of preoperative PROMs between CSM and OPLL groups revealed differences in age, body mass index, and EQ-5D-3L scores. The CSM group had higher NDI scores for concentration and lower EQ-5D-3L scores for self-care compared to the OPLL group.

CONCLUSIONS

This study validated the preoperative Japanese COMI-Neck in CSM and OPLL patients and identified specific QOL issues associated with each condition. The findings highlight the importance of considering disease-specific QOL and tailoring treatment plans accordingly. Further research should include postoperative assessments and a more diverse population to enhance generalizability.

Evaluation of Genetic and Nongenetic Risk Factors for Degenerative Cervical Myelopathy

STUDY DESIGN

Cohort study.

OBJECTIVE

We aimed to evaluate the associations of genetic and nongenetic factors with degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

There is mounting evidence for an inherited predisposition for DCM, but uncertainty remains regarding specific genetic markers involved. Similarly, nongenetic factors are thought to play a role.

MATERIALS AND METHODS

Using diagnosis codes from hospital records linked to the UK Biobank cohort, patients with cervical spondylosis were identified followed by the identification of a subset with DCM. Nongenetic variables evaluated included age, sex, race, Townsend deprivation index, body mass index, occupational demands, osteoporosis, and smoking. Genome-wide association analyses were conducted using logistic regression adjusted for age, sex, population principal components, and follow-up.

RESULTS

A total of 851 DCM cases out of 2787 cervical spondylosis patients were identified. Several nongenetic factors were independently associated with DCM including age [odds ratio (OR)=1.11, 95% CI=1.01-1.21, P =0.024], male sex (OR=1.63, 95% CI=1.37-1.93, P <0.001), and relative socioeconomic deprivation (OR=1.03, 95% CI=1.00-1.06, P =0.030). Asian race was associated with lower DCM risk (OR=0.44, 95% CI=0.22-0.85, P =0.014). We did not identify genome-wide significant (≤5×10 -8 ) single-nucleotide polymorphisms (SNPs) associated with DCM. The strongest genome-wide signals were at SNP rs67256809 in the intergenic region of the genes LINC02582 and FBXO15 on chromosome 18 ( P =1.12×10 -7 ) and rs577081672 in the GTPBP1 gene on chromosome 22 ( P =2.9×10 -7 ). No SNPs reported in prior DCM studies were significant after adjusting for replication attempts.

CONCLUSIONS

Increasing age, male sex, and relative socioeconomic deprivation were identified as independent risk factors for DCM, whereas Asian race was inversely associated. SNPs of potential interest were identified in GTPBP1 and an intergenic region on chromosome 18, but these associations did not reach genome-wide significance. Identification of genetic and nongenetic DCM susceptibility markers may guide understanding of DCM disease processes, inform risk, guide prevention and potentially inform surgical outcomes.

LEVEL OF EVIDENCE

Prognostic level III.

Methodology of economic evaluations in spine surgery: a systematic review and qualitative assessment

OBJECTIVES

The present study is a systematic review conducted as part of a methodological approach to develop evidence-based recommendations for economic evaluations in spine surgery. The aim of this systematic review is to evaluate the methodology and quality of currently available clinical cost-effectiveness studies in spine surgery.

STUDY DESIGN

Systematic literature review.

DATA SOURCES

PubMed, Web of Science, Embase, Cochrane, Cumulative Index to Nursing and Allied Health Literature, EconLit and The National Institute for Health Research Economic Evaluation Database were searched through 8 December 2022.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies were included if they met all of the following eligibility criteria: (1) spine surgery, (2) the study cost-effectiveness and (3) clinical study. Model-based studies were excluded.

DATA EXTRACTION AND SYNTHESIS

The following data items were extracted and evaluated: pathology, number of participants, intervention(s), year, country, study design, time horizon, comparator(s), utility measurement, effectivity measurement, costs measured, perspective, main result and study quality.

RESULTS

130 economic evaluations were included. Seventy-four of these studies were retrospective studies. The majority of the studies had a time horizon shorter than 2 years. Utility measures varied between the EuroQol 5 dimensions and variations of the Short-Form Health Survey. Effect measures varied widely between Visual Analogue Scale for pain, Neck Disability Index, Oswestry Disability Index, reoperation rates and adverse events. All studies included direct costs from a healthcare perspective. Indirect costs were included in 47 studies. Total Consensus Health Economic Criteria scores ranged from 2 to 18, with a mean score of 12.0 over all 130 studies.

CONCLUSIONS

The comparability of economic evaluations in spine surgery is extremely low due to different study designs, follow-up duration and outcome measurements such as utility, effectiveness and costs. This illustrates the need for uniformity in conducting and reporting economic evaluations in spine surgery.

A Five-Year Cost-Utility Analysis Comparing Synthetic Cage Versus Allograft Use in Anterior Cervical Discectomy and Fusion Surgery for Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective cost-utility analysis.

OBJECTIVE

To conduct a cost-analysis comparing synthetic cage (SC) versus allograft (Allo) over a five-year time horizon.

SUMMARY OF BACKGROUND DATA

SC and Allo are two commonly used interbody choices for anterior cervical discectomy and fusion (ACDF) surgery. Previous analyses comparative analyses have reached mixed conclusions regarding their cost-effectiveness, yet recent estimates provide high-quality evidence.

MATERIALS AND METHODS

A decision-analysis model comparing the use of Allo versus SC was developed for a hypothetical 60-year-old patient with cervical spondylotic myelopathy undergoing single-level ACDF surgery. A comprehensive literature review was performed to estimate probabilities, costs (2020 USD) and quality-adjusted life years (QALYs) gained over a five-year period. A probabilistic sensitivity analysis using a Monte Carlo simulation of 1000 patients was carried out to calculate incremental cost-effectiveness ratio and net monetary benefits. One-way deterministic sensitivity analysis was performed to estimate the contribution of individual parameters to uncertainty in the model.

RESULTS

The use of Allo was favored in 81.6% of the iterations at a societal willing-to-pay threshold of 50,000 USD/QALY. Allo dominated (higher net QALYs and lower net costs) in 67.8% of the iterations. The incremental net monetary benefits in the Allo group was 2650 USD at a willing-to-pay threshold of 50,000 USD/QALY. One-way deterministic sensitivity analysis revealed that the cost of the index surgery was the only factor which significantly contributed to uncertainty.

CONCLUSION

Cost-utility analysis suggests that Allo maybe a more cost-effective option compared with SCs in adult patients undergoing ACDF for cervical spondylotic myelopathy.

Determinants of quality of life in degenerative cervical myelopathy: a systematic review

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of chronic, progressive spinal cord impairment worldwide. Patients experience substantial pain, functional neurological decline and disability. Health-related quality of life (HRQoL) appears to be particularly poor, even when compared to other chronic diseases. However, the determinants of HRQoL are poorly understood. The objective was to perform a systematic review of the determinants of quality of life of people with DCM.

METHODS

A systematic search was conducted in MEDLINE and Embase following PRISMA 2020 guidelines (PROSPERO CRD42018115675). Full-text papers in English, exclusively studying DCM, published before 26 March 2020 were eligible for inclusion and were assessed using the Newcastle-Ottawa Scale and the Cochrane Risk of Bias 2 (RoB 2) tool. Study sample characteristics, patient demographics, cohort type, HRQoL instrument utilised, HRQoL score, and relationships of HRQoL with other variables were qualitatively synthesised.

RESULTS

A total of 1176 papers were identified; 77 papers and 13,572 patients were included in the final analysis. A total of 96% of papers studied surgical cohorts and 86% utilised the 36-Item Short Form Survey (SF-36) as a measure of HRQoL. HRQoL determinants were grouped into nine themes. The most common determinant to be assessed was surgical technique (38/77, 49%) and patient satisfaction and experience of pain (10/77, 13%). HRQoL appeared to improve after surgery. Pain was a negative predictor of HRQoL.

CONCLUSION

Current data on the determinants of HRQoL in DCM are limited, contradictory and heterogeneous. Limitations of this systematic review include lack of distinction between DCM subtypes and heterogenous findings amongst the papers in which HRQoL is measured postoperatively or post-diagnosis. This highlights the need for greater standardisation in DCM research to allow further synthesis. Studies of greater precision are necessary to account for HRQoL being complex, multi-factorial and both time and context dependent.

Comparison of Two Anterior Reconstructive Techniques in the Treatment of 3-Level and 4 Level Cervical Spondylotic Myelopathy: A Meta-analysis of Last Decade

Study Design

A meta-analysis.

Objective

Anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are widely used in the treatment of cervical spondylotic myelopathy (CSM). However, the clinical outcomes and complications between ACDF and ACCF treating multi-level CSM remain poorly understood. Thus, we performed a meta-analysis to compare the clinical outcomes and complications of the two procedures in the treatment of 3-level and 4-level CSM.

Methods

An extensive search of the literature was performed in the English databases of PubMed, Embase, and Cochrane Library and the Chinese databases of CNKI and WANFANG. We collected factors, including demographic data, surgical factors, and complications. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

Results

Finally, 14 articles (5429 patients) were included in our study. No significant difference was found in preoperative and 3-month follow-up Japanese Orthopedic Association (JOA) scores, neck disability index, preoperative C2-C7, segmental angle, operation time, as well as the number of dysphagia, hoarseness, cerebral fluid leakage, infection, epidural hematoma, axial pain, hardware breakage, and pseudarthrosis between ACDF and ACCF. However, our findings showed that blood loss (P < 0.00001), the number of total complications (P < 0 .00001), C5 palsy (P = 0.0004), graft dislodgement (P = 0.02), graft subsidence (P = 0.0003), and revision surgery (P = 0.0008) in ACDF were significantly less than in ACCF. Additionally, postoperative and change of C2-C7 (P < 0.00001), segment angle (P < 0.00001), and fusion rate (P = 0.001) in ACDF were significantly higher than in ACCF. Post-operative JOA in ACDF was significantly higher than in ACCF (P = 0.02).

Conclusions

Although the clinical efficacy of both surgeries was similar, ACDF was superior to ACCF in the reconstruction of cervical lordosis and the number of complications in the treatment of 3-level and 4-level CSM.

Establishing the Socio-Economic Impact of Degenerative Cervical Myelopathy Is Fundamental to Improving Outcomes [AO Spine RECODE-DCM Research Priority Number 8]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To contextualize AO Spine RECODE-DCM research priority number 5: What is the socio-economic impact of DCM? (The financial impact of living with DCM to the individual, their supporters, and society as a whole).

METHODS

In this review, we introduce the methodology of health-economic investigation, including potential techniques and approaches. We summarize the current health-economic evidence within DCM, so far focused on surgical treatment. We also cover the first national estimate, in partnership with Myelopathy.org from the United Kingdom, of the cost of DCM to society. We then demonstrate the significance of this question to advancing care and outcomes in the field.

RESULTS

DCM is a common and often disabling condition, with a significant lack of recognition. While evidence demonstrates the cost-effectives of surgery, even among higher income countries, health inequalities exist. Further the prevalent residual disability in myelopathy, despite treatment affects both the individual and society as a whole. A report from the United Kingdom provides the first cost-estimate to their society; an annual cost of ∼£681.6 million per year, but this is likely a significant underestimate.

CONCLUSION

A clear quantification of the impact of DCM is needed to raise the profile of a common and disabling condition. Current evidence suggests this is likely to be globally substantial.

Improving Awareness Could Transform Outcomes in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 1]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To introduce the number one research priority for Degenerative Cervical Myelopathy (DCM): Raising Awareness.

METHODS

Raising awareness has been recognized by AO Spine RECODE-DCM as the number one research priority. This article reviews the evidence that awareness is low, the potential drivers, and why this must be addressed. Case studies of success from other diseases are also reviewed, drawing potential parallels and opportunities for DCM.

RESULTS

DCM may affect as many as 1 in 50 adults, yet few will receive a diagnosis and those that do will wait many years for it. This leads to poorer outcomes from surgery and greater disability. DCM is rarely featured in healthcare professional training programs and has received relatively little research funding (<2% of Amyotrophic Lateral Sclerosis or Multiple Sclerosis over the last 25 years). The transformation of stroke and acute coronary syndrome services, from a position of best supportive care with occasional surgery over 50 years ago, to avoidable disability today, represents transferable examples of success and potential opportunities for DCM. Central to this is raising awareness.

CONCLUSION

Despite the devastating burden on the patient, recognition across research, clinical practice, and healthcare policy are limited. DCM represents a significant unmet need that must become an international public health priority.

Degenerative Cervical Myelopathy in Higher-Aged Patients: How Do They Benefit from Surgery?

Background: Degenerative cervical myelopathy (DCM) is the most common reason for spinal cord disease in elderly patients. This study analyzes the preoperative status and postoperative outcome of higher-aged patients in comparison to young and elderly patients in order to determine the benefit to those patients from DCM surgery. Methods: A retrospective analysis of the clinical data, radiological findings, and operative reports of 411 patients treated surgically between 2007 and 2016 suffering from DCM was performed. The preoperative and postoperative neurological functions were evaluated using the modified Japanese Orthopedic Association Score (mJOA Score), the postoperative mJOA Score improvement, the neurological recovery rate (NRR) of the mJOA Score, and the minimum clinically important difference (MCID). The Charlson Comorbidity Index (CCI) was used to evaluate the impact of comorbidities on the preoperative and postoperative mJOA Score. The comparisons were performed between the following age groups: G1: ≤50 years, G2: 51–70 years, and G3: >70 years. Results: The preoperative and postoperative mJOA Score was significantly lower in G3 than in G2 and G1 (p < 0.0001). However, the mean mJOA Score’s improvement did not differ significantly (p = 0.81) between those groups six months after surgery (G1: 1.99 ± 1.04, G2: 2.01 ± 1.04, G: 2.00 ± 0.91). Furthermore, the MCID showed a significant improvement in every age-group. The CCI was evaluated for each age-group, showing a statistically significant group effect (p < 0.0001). Analysis of variance revealed a significant group effect on the delay (weeks) between symptom onset and surgery (p = 0.003). The duration of the stay at the hospital did differ significantly between the age groups (p < 0.0001). Conclusion: Preoperative and postoperative mJOA Scores, but not the extent of postoperative improvement, are affected by the patients’ age. Therefore, patients should be considered for DCM surgery regardless of their age.

Value of Surgery and Nonsurgical Approaches for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

Cervical spondylotic myelopathy (CSM) is a common cause of adult spinal cord dysfunction. Although the therapeutic options for moderate to severe CSM patients have been established well, the existing guidelines for therapeutic decisions in mild cases of CSM are unclear. We present a review of literature on conservative treatment and surgery for CSM and suggest general recommendations applicable in various clinical presentations and in different geographic locations across the globe, with due considerations to available resources and locally prevalent practices.

The DOWN Questionnaire: A Novel Screening Tool for Cervical Spondylotic Myelopathy

STUDY DESIGN

Case-control study.

OBJECTIVES

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord injury in adults aged over 55 years. However, since the onset is typically insidious, accurately diagnosing CSM can be challenging, often requiring referral to a subspecialist and advanced imaging. To help identify patients at risk for CSM, this case-control study compared responses to a series of 4 questions (DOWN questionnaire) in myelopathic and non-myelopathic patients.

METHODS

Ninety-two patients, 46 with and 46 without myelopathy, were recruited for the study. Each patient answered 4 questions encompassing common symptoms associated with CSM. Responses between patient groups were compared, and Cohen's κ was used to assess for agreement between responses and the diagnosis of myelopathy.

RESULTS

We found a sensitivity of 91% and a κ of 0.54 to 3 positive responses and a sensitivity of 72% and a κ of 0.61 to 4 positive responses.

CONCLUSIONS

Positive responses to 3 or more DOWN questions has high sensitivity and moderate agreement with the diagnosis of myelopathy based on history, physical exam, and review of advanced imaging by an orthopedic or neurological surgeon. The DOWN questionnaire is a potentially useful screening tool to identify patients at risk for CSM.

Degenerative Cervical Myelopathy: A 7-Letter Coding System That Supports Decision-Making for the Surgical Approach

Objective

To validate with a prospective study a decision-supporting coding system for the surgical approach for multilevel degenerative cervical myelopathy.

Methods

Ten cases were presented on an internet platform, including clinical and imaging data. A single-approach (G1), a choice between 2 (G2), or 3 approaches (G3) were options. Senior and junior spine surgeons analyzed 7 parameters: location and extension of the compression of the spinal cord, C-spine alignment and instability, general morbidity and bone diseases, and K-line and multilevel corpectomy. For each parameter, an anterior, posterior, or combined approach was suggested. The most frequent letter or the last letter (if C) of the resulting 7-letter code (7LC) suggested the surgical approach. Each surgeon performed 2 reads per case within 8 weeks.

Results

G1: Interrater reliability between junior surgeons improved from the first read (κ = 0.40) to the second (κ = 0.76, p < 0.001) but did not change between senior surgeons (κ = 0.85). The intrarater reliability was similar for junior (κ = 0.78) and senior (κ = 0.71) surgeons. G2: Junior/senior surgeons agreed completely (58%/62%), partially (24%/23%), or did not agree (18%/15%) with the 7LC choice. G3: junior/senior surgeons agreed completely (50%/50%) or partially (50%/50%) with the 7LC choice.

Conclusion

The 7LC showed good overall reliability. Junior surgeons went through a learning curve and converged to senior surgeons in the second read. The 7LC helps less experienced surgeons to analyze, in a structured manner, the relevant clinical and imaging parameters influencing the choice of the surgical approach, rather than simply pointing out the only correct one.

The Total Cost to the Health Care System in Medicare and Medicaid Patients for the Treatment of Cervical Myelopathy

INTRODUCTION

Cervical myelopathy is a common indication for spine surgery. Modern medicine demands high quality, cost-effective treatment. Most cost analyses fail to account for complication costs from nonoperative treatment. The purpose is to compare the total health care costs for operative versus nonoperative treatment of cervical myelopathy.

METHODS

The Center for Medicare and Medicaid Services Carrier File from 2005 to 2012 was reviewed using the PearlDiver database, representing a 5% sampling of Medicare billings which diagnosed patients with cervical myelopathy by International Classification of Diseases 9 code. Patients were separated into operative and nonoperative cohorts, and the total health care expenditures per patient normalized to 2012 dollars were collected.

RESULTS

A total of 3209 patients were included, and 1755 (55.87%) underwent surgery. A 6-year cost analysis performed on 309 patients over the age of 65 from 2006 undergoing surgery resulted in a nonsignificant increase in total health care expenditures ($166,192 vs. $153,556; P=0.45). Operative treatment had a net decrease in total health care costs following the first year of surgery.

CONCLUSIONS

There is no significant difference in the total health care expenditures for operative versus nonoperative treatment of cervical myelopathy after 3 years. It is critical to understand that nonoperative treatment of this progressive disease leads to a substantial increase in total health care expenditures with increased risk of falls, injury, and further morbidity.

Quality of Life in Patients Undergoing Spine Surgery: Systematic Review and Meta-Analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVE

Despite the increasing importance of tracking clinical outcomes using valid patient-reported outcome measures, most providers do not routinely obtain baseline preoperative health-related quality of life (HRQoL) data in patients undergoing spine surgery, precluding objective outcomes analysis in individual practices. We conducted a meta-analysis of pre- and postoperative HRQoL data obtained from the most commonly published instruments to use as reference values.

METHODS

We searched PubMed, EMBASE, and an institutional registry for studies reporting EQ-5D, SF-6D, and Short Form-36 Physical Component Summary scores in patients undergoing surgery for degenerative cervical and lumbar spinal conditions published between 2000 and 2014. Observational data was pooled meta-analytically using an inverse variance-weighted, random-effects model, and statistical comparisons were performed.

RESULTS

Ninety-nine articles were included in the final analysis. Baseline HRQoL scores varied by diagnosis for each of the 3 instruments. On average, postoperative HRQoL scores significantly improved following surgical intervention for each diagnosis using each instrument. There were statistically significant differences in baseline utility values between the EQ-5D and SF-6D instruments for all lumbar diagnoses.

CONCLUSIONS

The pooled HRQoL values presented in this study may be used by practitioners who would otherwise be precluded from quantifying their surgical outcomes due to a lack of baseline data. The results highlight differences in HRQoL between different degenerative spinal diagnoses, as well as the discrepancy between 2 common utility-based instruments. These findings emphasize the need to be cognizant of the specific instruments used when comparing the results of outcome studies.

Development of the Portuguese Version of the Modified Japanese Orthopaedic Association Score: Cross-Cultural Adaptation, Reliability, Validity, and Responsiveness

BACKGROUND

Spondylotic cervical myelopathy (SCM) is a common cause of spinal-related disability in elderly patients. The assessment of this disability is a challenging task and depends on the subjective evaluation of the investigator. As a widespread-used scale, the modified version of the Japanese Orthopaedic Association score (mJOA) should be translated and culturally adapted in the Brazilian Portuguese language (i.e., mJOA-Br) to provide its clinical and research use. This study aimed to perform translation, transcultural adaptation, and validation of the mJOA into Brazilian Portuguese.

METHODS

Following the transcultural adaptation model described by Guillemin et al., the scale as translated into Brazilian Portuguese and back-translated to English. Afterwards, questionnaires were applied in consecutive patients with SCM and compared with a control group (without SCM). The final scale was compared with the Brazilian version of Neck Disability Index for validation.

RESULTS

Sixty patients were submitted to the translated version of mJOA. There was a strong correlation between mJOA-Br scores and Neck Disability Index scores to evaluate SCM symptoms (R = -0.75).

CONCLUSIONS

mJOA-Br was considered a valid and reliable tool to evaluate patients with SCM.

Quantitative assessment of hand motor function in cervical spinal disorder patients using target tracking tests

Cervical spondylotic myelopathy (CSM) is a chronic spinal disorder in the neck region. Its prevalence is growing rapidly in developed nations, creating a need for an objective assessment tool. This article introduces a system for quantifying hand motor function using a handgrip device and target tracking test. In those with CSM, hand motor impairment often interferes with essential daily activities. The analytic method applied machine learning techniques to investigate the efficacy of the system in (1) detecting the presence of impairments in hand motor function, (2) estimating the perceived motor deficits of CSM patients using the Oswestry Disability Index (ODI), and (3) detecting changes in physical condition after surgery, all of which were performed while ensuring test-retest reliability. The results based on a pilot data set collected from 30 patients with CSM and 30 nondisabled control subjects produced a c-statistic of 0.89 for the detection of impairments, Pearson r of 0.76 with p < 0.001 for the estimation of ODI, and a c-statistic of 0.82 for responsiveness. These results validate the use of the presented system as a means to provide objective and accurate assessment of the level of impairment and surgical outcomes.

Propensity-matched Analysis of Outcomes and Hospital Charges for Anterior Versus Posterior Cervical Fusion for Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective analysis of data from the Nationwide Inpatient Sample, a nationally representative, all-payer database of inpatient diagnoses and procedures in the United States.

OBJECTIVE

The objective of this study is to compare anterior cervical fusion (ACF) to posterior cervical fusion (PCF) in the treatment of cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Previous studies used retrospective single-institution level data to quantify outcomes for CSM patients fusion. It is unclear whether ACF or PCF is superior with regards to charges or outcomes for the treatment of CSM.

MATERIALS AND METHODS

We used Nationwide Inpatient Sample data to compare ACF to PCF in the management of CSM. All patients 18 years or older with a diagnosis of CSM between 1998 and 2011 were included. ACF patients were matched to PCF patients using propensity scores based on patient characteristics (number of levels fused, spine alignment, comorbidities), hospital characteristics, and patient demographics. Multivariable regression was used to measure the effect of treatment assignment on in-hospital charges, length of hospital stay, in-hospital mortality, discharge disposition, and dysphagia diagnosis.

RESULTS

From 1998 to 2011, we identified 109,728 hospitalizations with a CSM diagnosis. Of these patients, 45,629 (41.6%) underwent ACF and 14,439 (13.2%) underwent PCF. The PCF cohort incurred an average of $41,683 more in-hospital charges (P<0.001, inflation adjusted to 2011 dollars) and remained in hospital an average of 2.4 days longer (P<0.001) than the ACF cohort. The ACF cohort was just as likely to die in the hospital [odds ratio 0.91; 95% confidence interval (CI), 0.68-1.2], 3.0 times more likely to be discharged to home or self-care (95% CI, 2.9-3.2), and 2.5 times more likely to experience dysphagia (95% CI, 2.0-3.1) than the PCF cohort.

CONCLUSIONS

In treating CSM, ACF led to lower hospital charges, shorter hospital stays, and an increased likelihood of being discharged to home relative to PCF.

Health Economics and the Management of Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord impairment worldwide. Surgical intervention has been demonstrated to be effective and is becoming standard of care. Spine surgery, however, is costly and value needs to be demonstrated. This review serves to summarize the key health economic concepts as they relate to the assessment of the value of surgery for DCM. This is followed by a discussion of current health economic research on DCM, which suggests that surgery is likely to be cost effective. The review concludes with a summary of future questions that remain unanswered, such as which patient subgroups derive the most value from surgery and which surgical approaches are the most cost effective.

Current Diagnosis and Management of Cervical Spondylotic Myelopathy

STUDY DESIGN

Review.

OBJECTIVES

Cervical spondylotic myelopathy (CSM) is a major cause of disability, particular in elderly patients. Awareness and understanding of CSM is imperative to facilitate early diagnosis and management. This review article addresses CSM with regard to its epidemiology, anatomical considerations, pathophysiology, clinical manifestations, imaging characteristics, treatment approaches and outcomes, and the cost-effectiveness of surgical options.

METHODS

The authors performed an extensive review of the peer-reviewed literature addressing the aforementioned objectives.

RESULTS

The clinical presentation and natural history of CSM is variable, alternating between quiescent and insidious to stepwise decline or rapid neurological deterioration. For mild CSM, conservative options could be employed with careful observation. However, surgical intervention has shown to be superior for moderate to severe CSM. The success of operative or conservative management of CSM is multifactorial and high-quality studies are lacking. The optimal surgical approach is still under debate, and can vary depending on the number of levels involved, location of the pathology and baseline cervical sagittal alignment.

CONCLUSIONS

Early recognition and treatment of CSM, before the onset of spinal cord damage, is essential for optimal outcomes. The goal of surgery is to decompress the cord with expansion of the spinal canal, while restoring cervical lordosis, and stabilizing when the risk of cervical kyphosis is high. Further high-quality randomized clinical studies with long-term follow up are still needed to further define the natural history and help predict the ideal surgical strategy.

Change in Functional Impairment, Disability, and Quality of Life Following Operative Treatment for Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVES

The primary objective of this systematic review was to define the change in impairment, disability, and pain following surgical intervention in patients with degenerative cervical myelopathy (DCM). Secondary objectives included to assess the impact of preoperative disease severity and duration of symptoms on outcomes and to summarize complications associated with surgery.

METHODS

A systematic literature search was conducted to identify prospective studies evaluating the effectiveness and safety of operative treatment in patients with DCM. Outcomes of interest were functional status, disability, pain, and complications. The quality of each study was evaluated using the Newcastle-Ottawa Scale, and the strength of the overall body of evidence was rated using guidelines outlined by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) Working Group.

RESULTS

Of the 385 retrieved citations, 32 met inclusion criteria and are summarized in this review. Based on our results, pooled standard mean differences showed a large effect for improvement in Japanese Orthopaedic Association or modified Japanese Orthopaedic Association score from baseline at short-, medium-, and long-term follow-up: 6 to 12 months (1.92; 95% confidence interval [CI] = 1.41 to 2.43), 13 to 36 months (1.40; 95% CI = 1.12 to 1.67), and ≥36 months (1.92; 95% CI = 1.14 to 2.69) (moderate evidence). Surgery also resulted in significant improvements in Nurick, Neck Disability Index, and Visual Analogue Scale scores (low to very low evidence). The cumulative incidence of complications was low (14.1%; 95% CI = 10.1% to 18.2%).

CONCLUSION

Surgical intervention for DCM results in significant improvements in functional impairment, disability, and pain and is associated with an acceptably low rate of complications.

A Clinical Practice Guideline for the Management of Patients With Degenerative Cervical Myelopathy: Recommendations for Patients With Mild, Moderate, and Severe Disease and Nonmyelopathic Patients With Evidence of Cord Compression

STUDY DESIGN

Guideline development.

OBJECTIVES

The objective of this study is to develop guidelines that outline how to best manage (1) patients with mild, moderate, and severe myelopathy and (2) nonmyelopathic patients with evidence of cord compression with or without clinical symptoms of radiculopathy.

METHODS

Five systematic reviews of the literature were conducted to synthesize evidence on disease natural history; risk factors of disease progression; the efficacy, effectiveness, and safety of nonoperative and surgical management; the impact of preoperative duration of symptoms and myelopathy severity on treatment outcomes; and the frequency, timing, and predictors of symptom development. A multidisciplinary guideline development group used this information, and their clinical expertise, to develop recommendations for the management of degenerative cervical myelopathy (DCM).

RESULTS

Our recommendations were as follows: (1) "We recommend surgical intervention for patients with moderate and severe DCM." (2) "We suggest offering surgical intervention or a supervised trial of structured rehabilitation for patients with mild DCM. If initial nonoperative management is pursued, we recommend operative intervention if there is neurological deterioration and suggest operative intervention if the patient fails to improve." (3) "We suggest not offering prophylactic surgery for non-myelopathic patients with evidence of cervical cord compression without signs or symptoms of radiculopathy. We suggest that these patients be counseled as to potential risks of progression, educated about relevant signs and symptoms of myelopathy, and be followed clinically." (4) "Non-myelopathic patients with cord compression and clinical evidence of radiculopathy with or without electrophysiological confirmation are at a higher risk of developing myelopathy and should be counselled about this risk. We suggest offering either surgical intervention or nonoperative treatment consisting of close serial follow-up or a supervised trial of structured rehabilitation. In the event of myelopathic development, the patient should be managed according to the recommendations above."

CONCLUSIONS

These guidelines will promote standardization of care for patients with DCM, decrease the heterogeneity of management strategies and encourage clinicians to make evidence-informed decisions.

Socioeconomic and regional differences in the treatment of cervical spondylotic myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) is the leading cause of spinal cord dysfunction in the world. Surgical treatment is both medically and economically advantageous, and can be achieved through multiple approaches, with or without fusion. We used the Nationwide Inpatient Sample (NIS) database to better elucidate regional and socioeconomic variances in the treatment of CSM.

METHODS

The NIS database was queried for elective admissions with a primary diagnosis of CSM (ICD-9 721.1). This was evaluated for patients who also carried a diagnosis of anterior (ICD-9 81.02) or posterior cervical fusion (ICD-9 81.03), posterior cervical laminectomy (ICD 03.09), or a combination. We then investigated variances including regional trends and disparities according to hospital and insurance types.

RESULTS

During 2002-2012, 50605 patients were electively admitted with a diagnosis of CSM. Anterior fusions were more common in Midwestern states and in nonteaching hospitals. Fusion procedures were used more frequently than other treatments in private hospitals and with private insurance. Median hospital charges were also expectedly higher for fusion procedures and combined surgical approaches. Combined approaches were found to be significantly greater in patients with concurrent diagnoses of ossification of the posterior longitudinal ligament (OPLL) and CSM. Ultimately, there has been an increased utilization of fusion procedures versus nonfusion treatments, over the past decade, for patients with cervical myelopathy.

CONCLUSIONS

Fusion surgery is being increasingly used for the treatment of CSM. Expensive procedures are being performed more frequently in both private hospitals and for those with private insurance, whereas the most economical procedure, posterior cervical laminectomy, was underutilized.

The reporting of study and population characteristics in degenerative cervical myelopathy: A systematic review

OBJECT

Degenerative cervical myelopathy [DCM] is a disabling and increasingly prevalent condition. Variable reporting in interventional trials of study design and sample characteristics limits the interpretation of pooled outcomes. This is pertinent in DCM where baseline characteristics are known to influence outcome. The present study aims to assess the reporting of the study design and baseline characteristics in DCM as the premise for the development of a standardised reporting set.

METHODS

A systematic review of MEDLINE and EMBASE databases, registered with PROSPERO (CRD42015025497) was conducted in accordance with PRISMA guidelines. Full text articles in English, with >50 patients (prospective) or >200 patients (retrospective), reporting outcomes of DCM were deemed to be eligible.

RESULTS

A total of 108 studies involving 23,876 patients, conducted world-wide, were identified. 33 (31%) specified a clear primary objective. Study populations often included radiculopathy (51, 47%) but excluded patients who had undergone previous surgery (42, 39%). Diagnositic criteria for myelopathy were often uncertain; MRI assessment was specified in only 67 (62%) of studies. Patient comorbidities were referenced by 37 (34%) studies. Symptom duration was reported by 46 (43%) studies. Multivariate analysis was used to control for baseline characteristics in 33 (31%) of studies.

CONCLUSIONS

The reporting of study design and sample characteristics is variable. The development of a consensus minimum dataset for (CODE-DCM) will facilitate future research synthesis in the future.

Surgery for degenerative cervical myelopathy: a patient-centered quality of life and health economic evaluation

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) represents the most common cause of non-traumatic spinal cord impairment in adults. Surgery has been shown to improve neurologic symptoms and functional status, but it is costly. As sustainability concerns in the field of health care rise, the value of care has come to the forefront of policy decision-making. Evidence for both health-related quality of life outcomes and financial expenditures is needed to inform resource allocation decisions.

PURPOSE

This study aimed to estimate the lifetime incremental cost-utility of surgical treatment for DCM.

DESIGN/SETTING

This is a prospective observational cohort study at a Canadian tertiary care facility.

PATIENT SAMPLE

We recruited all patients undergoing surgery for DCM at a single center between 2005 and 2011 who were enrolled in either the AOSpine Cervical Spondylotic Myelopathy (CSM)-North America study or the AOSpine CSM-International study.

OUTCOME MEASURES

Health utility was measured at baseline and at 6, 12, and 24 months following surgery using the Short Form-6D (SF-6D) health utility score. Resource expenditures were calculated on an individual level, from the hospital payer perspective over the 24-month follow-up period. All costs were obtained from a micro-cost database maintained by the institutional finance department and reported in Canadian dollars, inflated to January 2015 values.

METHODS

Quality-adjusted life year (QALY) gains for the study period were determined using an area under the curve calculation with a linear interpolation estimate. Lifetime incremental cost-to-utility ratios (ICUR) for surgery were estimated using a Markov state transition model. Structural uncertainty arising from lifetime extrapolation and the single-arm cohort design of the study were accounted for by constructing two models. The first included a highly conservative assumption that individuals undergoing nonoperative management would not experience any lifetime neurologic decline. This constraint was relaxed in the second model to permit more general parameters based on the established natural history. Deterministic and probabilistic sensitivity analyses were employed to account for parameter uncertainty. All QALY gains and costs were discounted at a base of 3% per annum. Statistical significance was set at the .05 level.

RESULTS

The analysis included 171 patients; follow-up was 96.5%. Mean age was 58.2±12.0 years and baseline health utility was 0.56±0.14. Mean QALY gained over the 24-month study period was 0.139 (95% confidence interval: 0.109-0.170, p<.001) and the mean 2-year cost of treatment was $19,217.82±12,404.23. Cost associated with the operation comprised 65.7% of the total. The remainder was apportioned over presurgical preparation and postsurgical recovery. Three patients required a reoperation over the 2-year follow-up period. The costs of revision surgery represented 1.85% of the total costs. Using the conservative model structure, the estimated lifetime ICUR of surgical intervention was $20,547.84/QALY gained, with 94.7% of estimates falling within the World Health Organization definition of "very cost-effective" ($54,000 CAD). Using the more general model structure, the estimated lifetime ICUR of surgical intervention was $11,496.02/QALY gained, with 97.9% of estimates meeting the criteria to be considered "very cost-effective."

CONCLUSIONS

Surgery for DCM is associated with a significant quality of life improvement. The intervention is cost-effective and, from the perspective of the hospital payer, should be supported.

Does age affect surgical outcomes in patients with degenerative cervical myelopathy? Results from the prospective multicenter AOSpine International study on 479 patients

BACKGROUND

In general, older patients with degenerative cervical myelopathy (DCM) are felt to have lower recovery potential following surgery due to increased degenerative pathology, comorbidities, reduced physiological reserves and age-related changes to the spinal cord. This study aims to determine whether age truly is an independent predictor of surgical outcome and to provide evidence to guide practice and decision-making.

METHODS

A total of 479 patients with DCM were prospectively enrolled in the CSM-International study at 16 centres. Our sample was divided into a younger group (<65 years) and an elderly (≥65 years) group. A mixed model analytic approach was used to evaluate differences in the modified Japanese Orthopaedic Association (mJOA), Nurick, Short Form-36 (SF-36) and Neck Disability Index (NDI) scores between groups. We first created an unadjusted model between age and surgical outcome and then developed two adjusted models that accounted for variations in (1) baseline characteristics and (2) both baseline and surgical factors.

RESULTS

Of the 479 patients, 360 (75.16%) were <65 years and 119 (24.84%) were ≥65 years. Elderly patients had a worse preoperative health status (p<0.0001) and were functionally more severe (p<0.0001). The majority of younger patients (64.96%) underwent anterior surgery, whereas the preferred approach in the elderly group was posterior (58.62%, p<0.0001). Elderly patients had a greater number of decompressed levels than younger patients (p<0.0001). At 24 months after surgery, younger patients achieved a higher postoperative mJOA (p<0.0001) and a lower Nurick score (p<0.0001) than elderly patients. After adjustments for patient and surgical characteristics, these differences in postoperative outcome scores decreased but remained significant.

CONCLUSIONS

Older age is an independent predictor of functional status in patients with DCM. However, patients over 65 with DCM still achieve functionally significant improvement after surgical decompression.

Comparing Utility Scores in Common Spinal Radiculopathies: Results of a Prospective Valuation Study

Study Design Prospective observational study. Objective To determine whether preference-based health utility scores for common spinal radiculopathies vary by specific spinal level. Methods We employed a standard gamble study using the general public to calculate individual preference-based quality of life for four common radiculopathies: C6, C7, L5, and S1. We compared utility scores obtained for each level of radiculopathy with analysis of variance and t test. Multivariable regression was used to test the effects of the covariates age, sex, and years of education. We also reviewed the literature for publications reporting EuroQol-5 Dimensions (EQ-5D) scores for patients with radiculopathy. Results Two hundred participants were included in the study. Average utility for the four spinal levels fell within a narrow range (0.748 to 0.796). There were no statistically significant differences between lumbar and cervical radiculopathies, nor were there significant differences among the different spinal levels (F = 0.0850, p = 0.086). Age and sex had no significant effect on utility scores. There was a significant correlation between years of education and utility values for S1 radiculopathy (p = 0.037). On review of the literature, no study separated utility values by specific spinal level. EQ-5D utilities for both cervical and lumbar radiculopathy were considerably lower than the results of our study. Conclusions Utility values associated with the most common levels of cervical and lumbar radiculopathy do not significantly differ from each other, validating the current practice of grouping utility by spinal segment rather than by specific root levels. The discrepancy in average utility values between our study and the EQ-5D highlights the need to be mindful of the underlying instruments used when assessing outcomes studies from different sources.

Economic value of treating lumbar disc herniation in Brazil

OBJECT

Lumbar discectomy is one of the most common surgical spine procedures. In order to understand the value of this surgical care, it is important to understand the costs to the health care system and patient for good results. The objective of this study was to evaluate for the first time the cost-effectiveness of spine surgery in Latin America for lumbar discectomy in terms of cost per quality-adjusted life year (QALY) gained for patients in Brazil.

METHODS

The authors performed a prospective cohort study involving 143 consecutive patients who underwent open discectomy for lumbar disc herniation (LDH). Patient-reported outcomes were assessed utilizing the SF-6D, which is derived from a 12-month variation of the SF-36. Direct medical costs included medical reimbursement, costs of hospital care, and overall resource consumption. Disability losses were considered indirect costs. A 4-year horizon with 3% discounting was applied to health-utilities estimates. Sensitivity analysis was performed by varying utility gain by 20%. The costs were expressed in Reais (R$) and US dollars ($), applying an exchange rate of 2.4:1 (the rate at the time of manuscript preparation).

RESULTS

The direct and indirect costs of open lumbar discectomy were estimated at an average of R$3426.72 ($1427.80) and R$2027.67 ($844.86), respectively. The mean total cost of treatment was estimated at R$5454.40 ($2272.66) (SD R$2709.17 [$1128.82]). The SF-6D utility gain was 0.044 (95% CI 0.03197–0.05923, p = 0.017) at 12 months. The 4-year discounted QALY gain was 0.176928. The estimated cost-utility ratio was R$30,828.35 ($12,845.14) per QALY gained. The sensitivity analysis showed a range of R$25,690.29 ($10,714.28) to R$38,535.44 ($16,056.43) per QALY gained.

CONCLUSIONS

The use of open lumbar discectomy to treat LDH is associated with a significant improvement in patient outcomes as measured by the SF-6D. Open lumbar discectomy performed in the Brazilian supplementary health care system provides a cost-utility ratio of R$30,828.35 ($12,845.14) per QALY. The value of acceptable cost-effectiveness will vary by country and region.

Decision analytic modeling in spinal surgery: a methodologic overview with review of current published literature

BACKGROUND CONTEXT

In recent years, there has been an increase in the number of decision analysis studies in the spine literature. Although there are several published reviews on the different types of decision analysis (cost-effectiveness, cost-benefit, cost-utility), there is limited information in the spine literature regarding the mathematical models used in these studies (decision tree, Markov modeling, Monte Carlo simulation).

PURPOSE

The purpose of this review was to provide an overview of the types of decision analytic models used in spine surgery. A secondary aim was to provide a systematic overview of the most cited studies in the spine literature.

STUDY DESIGN/SETTING

This is a systematic review of the available information from all sources regarding decision analytics and economic modeling in spine surgery.

METHODS

A systematic search of PubMed, Embase, and Cochrane review was performed to identify the most relevant peer-reviewed literature of decision analysis/cost-effectiveness analysis (CEA) models including decisions trees, Markov models, and Monte Carlo simulations. Additionally, CEA models based on investigational drug exemption studies were reviewed in particular detail, as these studies are prime candidates for economic modeling.

RESULTS

The initial review of the literature resulted in 712 abstracts. After two reviewer-assessment of abstract relevance and methodologic quality, 19 studies were selected: 12 with decision tree constructs and 7 with Markov models. Each study was assessed for methodologic quality and a review of the overall results of the model. A generalized overview of the mathematical construction and methodology of each type of model was also performed. Limitations, strengths, and potential applications to spine research were further explored.

CONCLUSIONS

Decision analytic modeling represents a powerful tool both in the assessment of competing treatment options and potentially in the formulation of policy and reimbursement. Our review provides a generalized overview and a conceptual framework to help spine physicians with the construction of these models.

A global perspective on the outcomes of surgical decompression in patients with cervical spondylotic myelopathy: results from the prospective multicenter AOSpine international study on 479 patients

STUDY DESIGN

Prospective, multicenter international cohort.

OBJECTIVE

To evaluate outcomes of surgical decompression for cervical spondylotic myelopathy (CSM) at a global level.

SUMMARY OF BACKGROUND DATA

CSM is a degenerative spine disease and the most common cause of spinal cord dysfunction worldwide. Surgery is increasingly recommended as the preferred treatment strategy for CSM to improve neurological and functional status and quality of life. The outcomes of surgical intervention for CSM have never been evaluated at an international level.

METHODS

Between October 2007 and January 2011, 479 symptomatic patients with image evidence of CSM were enrolled in the prospective, multicenter AOSpine CSM-International study from 16 global sites. Preoperative and postoperative clinical status, functional impairment, and quality of life were evaluated using the modified Japanese Orthopaedic Assessment Scale, Nurick Scale, Neck Disability Index, and Short-Form-36v2. Preoperative and 12- and 24-month postoperative outcomes were compared using mixed-model analysis of covariance for repeated measurements.

RESULTS

The study cohort consisted of 310 males and 169 females, with a mean age of 56.37 ± 11.91 years. There were significant differences in age, etiology, and surgical approaches between the regions. At 24 months postoperatively, the mean modified Japanese Orthopaedic Assessment Scale score improved from 12.50 (95% confidence interval [CI], 12.24-12.76) to 14.90 (95% CI, 14.64-15.16); the Neck Disability Index improved from 36.38 (95% CI, 34.33-38.43) to 23.20 (95% CI, 21.24-25.15); and the SF36v2 Physical Component Score and Mental Composite Score improved from 34.28 (95% CI, 33.46-35.10) to 40.76 (95% CI, 39.71-41.81) and 39.45 (95% CI, 38.25-40.64) to 46.24 (95% CI, 44.94-47.55), respectively. The rate of neurological complications was 3.13%.

CONCLUSION

Surgical decompression for CSM is safe and results in improved functional status and quality of life in patients around the world, irrespective of differences in medical systems and sociocultural determinants of health.

LEVEL OF EVIDENCE

3.

Variations in cost calculations in spine surgery cost-effectiveness research

OBJECT

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 of this study was to systematically review all cost-effectiveness studies published on spine surgery and compare and contrast various costing methodologies used.

METHODS

The authors performed a systematic review of the cost-effectiveness literature related to spine surgery. All cost-effectiveness analyses pertaining to spine surgery were identified using the cost-effectiveness analysis registry database of the Tufts Medical Center Institute for Clinical Research and Health Policy, and the MEDLINE database. Each article was reviewed to determine the study subject, methodology, and results. Data were collected from each study, including costs, interventions, 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 10 (27%) involved the cervical spine. Of the 37 studies, 13 (35%) used Medicare reimbursements, 12 (32%) used a case-costing database, 3 (8%) used cost-to-charge ratios (CCRs), 2 (5%) used a combination of Medicare reimbursements and CCRs, 3 (8%) used the United Kingdom National Health Service 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 (30%) from the hospital perspective, and 7 (19%) from the payer perspective. Of those studies with a societal perspective, 14 (38%) 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 health care system based on the results of these studies.

Cost-effective studies in spine surgeries: a narrative review

BACKGROUND CONTEXT

Although the pathologic processes that affect the spine remain largely unchanged, our techniques to correct them continue to evolve with the development of novel medical and surgical interventions. Although the primary purpose of new technologies is to improve patients' quality of life, the economic impact of such therapies must be considered.

PURPOSE

To review the available peer-reviewed literature on spine surgery that addresses the cost-effectiveness of various treatments and technologies.

STUDY DESIGN

A narrative literature review.

METHODS

Articles published between January 1, 2000 and December 31, 2012 were selected from two Pubmed searches using keywords cost-effectiveness AND spine (216 articles) and cost analysis AND spine (358 articles). Relevant articles on cost analyses and cost-effectiveness were selected by the authors and reviewed.

RESULTS

Cervical and lumbar surgeries (anterior cervical discectomy and fusion, standard open lumbar discectomy, and standard posterior lumbar laminectomy) are reasonably cost effective at 2 years after the procedure (<100,000 US dollars per quality-adjusted life years gained) and become more cost effective with time because of sustained clinical improvements with relatively low additional incurred costs. The usage of transfusion avoidance technology is not cost effective because of the low risk of complications associated with allogenic transfusions. Although intraoperative neuromonitoring and imaging modalities are both cost saving and cost-effective, their cost-effectiveness is largely dependent on the baseline rate of neurologic complications and implant misplacement, respectively. More rigorous studies are needed to evaluate the cost-effectiveness of recombinant bone morphogenetic protein.

CONCLUSIONS

An ideal new technology should be able to achieve maximal improvement in patient health at a cost that society is willing to pay. The cost-effectiveness of technologies and treatments in spine care is dependent on their durability and the rate and severity of the baseline clinical problem that the treatment was designed to address.

The role of decision analytic modeling in the health economic assessment of spinal intervention

STUDY DESIGN

Narrative review.

OBJECTIVE

To review the common tenets, strengths, and weaknesses of decision modeling for health economic assessment and to review the use of decision modeling in the spine literature to date.

SUMMARY OF BACKGROUND DATA

For the majority of spinal interventions, well-designed prospective, randomized, pragmatic cost-effectiveness studies that address the specific decision-in-need are lacking. Decision analytic modeling allows for the estimation of cost-effectiveness based on data available to date. Given the rising demands for proven value in spine care, the use of decision analytic modeling is rapidly increasing by clinicians and policy makers.

METHODS

This narrative review discusses the general components of decision analytic models, how decision analytic models are populated and the trade-offs entailed, makes recommendations for how users of spine intervention decision models might go about appraising the models, and presents an overview of published spine economic models.

RESULTS

A proper, integrated, clinical, and economic critical appraisal is necessary in the evaluation of the strength of evidence provided by a modeling evaluation. As is the case with clinical research, all options for collecting health economic or value data are not without their limitations and flaws. There is substantial heterogeneity across the 20 spine intervention health economic modeling studies summarized with respect to study design, models used, reporting, and general quality. There is sparse evidence for populating spine intervention models. Results mostly showed that interventions were cost-effective based on $100,000/quality-adjusted life-year threshold. Spine care providers, as partners with their health economic colleagues, have unique clinical expertise and perspectives that are critical to interpret the strengths and weaknesses of health economic models.

CONCLUSION

Health economic models must be critically appraised for both clinical validity and economic quality before altering health care policy, payment strategies, or patient care decisions.

LEVEL OF EVIDENCE

4.

Cervical degenerative disease: systematic review of economic analyses

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 Cost-Effectiveness 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.

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.

LEVEL OF EVIDENCE

2.

Utilization of a novel digital measurement tool for quantitative assessment of upper extremity motor dexterity: a controlled pilot study

Background

The current methods of assessing motor function rely primarily on the clinician’s judgment of the patient’s physical examination and the patient’s self-administered surveys. Recently, computerized handgrip tools have been designed as an objective method to quantify upper-extremity motor function. This pilot study explores the use of the MediSens handgrip as a potential clinical tool for objectively assessing the motor function of the hand.

Methods

Eleven patients with cervical spondylotic myelopathy (CSM) were followed for three months. Eighteen age-matched healthy participants were followed for two months. The neuromotor function and the patient-perceived motor function of these patients were assessed with the MediSens device and the Oswestry Disability Index respectively. The MediSens device utilized a target tracking test to investigate the neuromotor capacity of the participants. The mean absolute error (MAE) between the target curve and the curve tracing achieved by the participants was used as the assessment metric. The patients’ adjusted MediSens MAE scores were then compared to the controls. The CSM patients were further classified as either “functional” or “nonfunctional” in order to validate the system’s responsiveness. Finally, the correlation between the MediSens MAE score and the ODI score was investigated.

Results

The control participants had lower MediSens MAE scores of 8.09%±1.60%, while the cervical spinal disorder patients had greater MediSens MAE scores of 11.24%±6.29%. Following surgery, the functional CSM patients had an average MediSens MAE score of 7.13%±1.60%, while the nonfunctional CSM patients had an average score of 12.41%±6.32%. The MediSens MAE and the ODI scores showed a statistically significant correlation (r=-0.341, p<1.14×10^-5). A Bland-Altman plot was then used to validate the agreement between the two scores. Furthermore, the percentage improvement of the the two scores after receiving the surgical intervention showed a significant correlation (r=-0.723, p<0.04).

Conclusions

The MediSens handgrip device is capable of identifying patients with impaired motor function of the hand. The MediSens handgrip scores correlate with the ODI scores and may serve as an objective alternative for assessing motor function of the hand.

Electronic supplementary material

The online version of this article (doi:10.1186/1743-0003-11-121) contains supplementary material, which is available to authorized users.

Comparison of anterior surgical options for the treatment of multilevel cervical spondylotic myelopathy: a systematic review

STUDY DESIGN

Systematic review.

OBJECTIVE

The primary objectives of this review were to compare the effectiveness and safety of various anterior cervical decompressive and reconstructive procedures for diffuse or multifocal cervical spondylotic myelopathy (CSM). An additional objective was to describe the most common ancillary stabilization techniques used with the different anterior decompressive procedures.

SUMMARY OF BACKGROUND DATA

Surgical management of CSM provides for neurological recovery and disease stabilization in a cost-effective way. Although both retrospective and prospective data support management of CSM by anterior cervical decompression and fusion, the choice decision between various anterior surgical options remains unclear.

METHODS

We conducted a systematic search in MEDLINE and the Cochrane Collaboration Library for human studies in the English-language literature published through September 2012. We included studies comparing multiple discectomies with single or multiple corpectomy, multiple discectomies with discectomy-corpectomy hybrid, and multiple corpectomies with discectomy-corpectomy hybrid, comparing effectiveness and safety outcomes of each procedure, and defining the ancillary stabilization techniques used. Exclusion criteria included patients with degenerative disc disease or degenerative joint disease without CSM, single-level CSM, ossified posterior longitudinal ligament (OPLL), spinal tumor, concomitant infection, and ankylozing spondylitis. Case series, case reports, data not reported separately for each comparison group, or studies that consisted of an N less than 10 for either comparison group were excluded. The evidence strength was rated using the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) criteria.

RESULTS

Of the 49 citations identified from our search, 10 studies were initially found suitable for inclusion. Patients undergoing any of the 3 procedures generally experienced improvements in clinical outcomes (neck disability index, Japanese Orthopaedic Association score, and Visual Analogue Scale score for pain) as well as overall sagittal alignment, with minimal perioperative morbidity. There is moderate evidence supporting selection of multiple discectomies compared with corpectomy or discectomy-corpectomy hybrid procedures with regard to superior clinical outcomes and postoperative sagittal alignment. Furthermore, if more extensive operation is needed, there is evidence to support the selection of discectomy-corpectomy hybrid procedures compared with multiple corpectomies if it is technically feasible to accomplish the requisite decompression. The multiple discectomies approach also may have a lower incidence of C5 palsy than corpectomy or discectomy-corpectomy hybrid approaches.

CONCLUSION

All 3 operative approaches are effective strategies for the anterior surgical management of CSM. When the patient pathoanatomy permits, selection of multiple discectomies is favored compared with corpectomy or discectomy-corpectomy hybrid approaches. EVIDENCE-BASED CLINICAL RECOMMENDATIONS:

RECOMMENDATION 1

When pathoanatomically appropriate with minimal retrovertebral disease, we recommend the selection of multiple discectomy over corpectomy or discectomy-corpectomy hybrid procedures.

OVERALL STRENGTH OF EVIDENCE

Low.

STRENGTH OF RECOMMENDATION

Strong.

RECOMMENDATION 2

When retrovertebral disease is significant, we recommend, when possible, that discectomy-corpectomy hybrid procedures be performed instead of multiple corpectomies.

OVERALL STRENGTH OF EVIDENCE

Moderate.

STRENGTH OF RECOMMENDATION

Strong. SUMMARY STATEMENTS: There is no evidence to guide choice of ancillary external immobilization techniques following multilevel anterior decompression and fusion procedures for CSM.

Ventral fusion versus dorsal fusion: determining the optimal treatment for cervical spondylotic myelopathy

Cervical spondylotic myelopathy (CSM) often can be surgically treated by either ventral or dorsal decompression and fusion. However, there is a lack of high-level evidence on the relative advantages and disadvantages for these treatments of CSM. The authors' goal was to provide a comprehensive review of the relative benefits of ventral versus dorsal fusion in terms of quality of life (QOL) outcomes, complications, and costs. They reviewed 7 studies on CSM published between 2003 and 2013 and summarized the findings for each category. Both procedures have been shown to lead to statistically significant improvement in clinical outcomes for patients. Ventral fusion surgery has been shown to yield better QOL outcomes than dorsal fusion surgery. Complication rates for ventral fusion surgery range from 11% to 13.6%, whereas those for dorsal fusion surgery range from 16.4% to 19%. Larger randomized controlled trials are needed, with particular emphasis on QOL and minimum clinically important differences.

Riluzole for acute traumatic spinal cord injury: a promising neuroprotective treatment strategy

BACKGROUND

Over the years, understanding of the specific secondary injury mechanisms that follow traumatic spinal cord injury (SCI) has improved. These pathologic mechanisms collectively serve to increase the extent of neural tissue injury, reducing prospects for neurologic recovery. An enhanced understanding of the pathobiology of SCI has permitted investigation of therapies targeting specific elements of this pathologic cascade. It is now known that the continuous posttraumatic activation of neuronal voltage-gated sodium ion channels leads to increased rates of cell death through the development of cellular swelling, acidosis, and glutaminergic excitotoxicity. The objective herein is to provide an update regarding the current status of the potential neuroprotective drug riluzole in the treatment of traumatic SCI.

METHODS

Narrative review and summary paper.

RESULTS

Riluzole is a sodium channel-blocking benzothiazole anticonvulsant drug that is approved by the U.S. Food and Drug Administration for the treatment of amyotrophic lateral sclerosis and has shown efficacy in preclinical models of SCI in reducing the extent of sodium and glutamate mediated secondary injury. This drug is currently under early stages of clinical investigation in SCI and shows promise as an acute neuroprotective therapy in this context.

CONCLUSION

This article reviews the biologic rationale, existing preclinical evidence, and emerging clinical data for riluzole in the treatment of traumatic SCI.