Appropriate Use Criteria
Neoplastic Vertebral Fracture
Methodology
A common methodology for AUC is the RAND/UCLA Appropriateness Method, a modified Delphi process, where AUCs are developed using evidence-based information in conjunction with the clinical expertise of physicians from multiple specialties.1 The NASS AUC methodology is closely patterned after the RAND method, although not identical. The rating process is the same, but more steps are taken in the pre-rating process to ensure precision of definitions and optimal development of scenarios. For this AUC, the topic was selected based on active clinical guideline development to utilize the literature search for both efforts and to create additional, complementary recommendations for the members.
Process:
1. AUC Groups. Members were assembled from NASS volunteers. Training in evidence-based medicine was helpful but not mandatory. Multispecialty representation was emphasized. National experts and/or thought leaders were selected.
2. Patient Population. The patient cohort encompassed adults (18 years or older) with symptoms related to neoplastic vertebral fractures. Inclusion and exclusion criteria are shown in Table 1.
Table 1. Inclusion and exclusion criteria as adapted by CPG.
3. Title. The title of the CPG “Neoplastic Vertebral Fracture” was also used for the AUC. Neoplastic fractures involved the cortical and or trabecular bone, thus may or may not represent decreased vertebral height. Thus, the term “compression” was not used in the title. The CPG was inclusive of metastatic and primary spine tumors. AUC focused on metastatic lesions only.
4. Standardization of Definitions. The definitions developed in the CPG for neoplastic vertebral fracture was used. Minor modifications of the definitions were made to further clarify the intent of the definition. (Table 2)
Table 2. Specific definitions utilized for this document
Neoplastic Vertebral Fracture Fracture of the vertebral body due to loss or destruction of cortical or trabecular bone from metastatic neoplastic process. Fractures may or may not be symptomatic and may or may not result in clinically significant deformity and/or neurologic deficit.
Spinal Stenosis Intraspinal bone and/or tumor that results in epidural effacement.
Complex Fracture
- Comminuted fracture of the trabecular and/or cortical bone
- With or without loss of integrity of the posterior wall
Note: all NVF are complex fractures
Mechanical Pain
- Pain localized to the site of fracture
- Intermittent in intensity, with predictable provocation, usually from load or movement
Nonmechanical Pain
- Generalized pain, relatively constant, not consistently provokable
Medical Therapy
- Chemotherapy
- Pharmacologic therapy
- Physical therapy
- Bracing
- Exercise
- Fall assessment and prevention
- Nutritional support
- Education
Radiation Treatment
- Conventional radiation
- Stereotactic body radiation therapy (SBRT)
- Proton beam
Cement Augmentation
- Includes kyphoplasty and vertebroplasty
Reconstructive Surgery
- Spinal instrumentation with or without fusion and/or decompression by MIS or open techniques
Ablation Radiofrequency ablation or cryoablation
Mechanical device-assisted cement augmentation
- Cage, stent, etc. with cement
- Included in the guidelines under cement augmentation for completeness, but not considered in the AUC
Prognosis This document assumes that prognosis for the patient has been determined based on the tumor type and their systemic health and burden of disease, and treatment has been accordingly determined to be appropriate. Within this population, there are those patients with generally poorer health and life expectancy, versus the opposite. We have made this dichotomous.
SINS (Spinal Instability Neoplastic Score) [PMID: 21709187]
- Purpose is to define stability based on scoring of 6 domains. Scoring outcomes: stable, indeterminant, unstable per the scoring system
- Location
- Pain
- Bone quality (lytic vs. blastic)
- Alignment (angular and translational)
- Vertebral body collapse
- Posterolateral element involved
**For this AUC, we have made this stable or unstable, and assume the provider can make the differentiation.
Radiosensitive There are a group of malignancies that are acknowledged to be highly radiosensitive. For the purpose of this AUC, the highly radiosensitive malignancies are considered sensitive, and the rest are insensitive, acknowledging there may be a wide spectrum of reduced sensitivity. It is assumed that that provider can differentiate the highly radiosensitive malignancies from the others.
Function
- Community ambulator – can function independently outside the home, with or without assistive device
- Homebound ambulator – Functionally homebound. May or may not be ambulatory within the home. Requires wheelchair to function outside home.
Literature Search1
Inclusion Criteria
- Age >18 years
- Spine or sacral fractures
- Single or multiple level fractures
- Simple or complex fractures
- With or without pain. Pain may be axial, radicular, generalized, or combination
Exclusion Criteria
- Acute or chronic spine infection including epidural abscess, discitis, and/or osteomyelitis
- Major trauma
- Prior surgery at the affected level
- Isolated intradural tumor Based on NVF guideline development
5. Scenario Writing. The key modifiers or variables were determined, and then a matrix of scenarios was developed based on these modifiers. (Table 3) The number of scenarios vary based on the breadth of the topic, but usually number in the hundreds. They are intended to describe most of the practical clinical scenarios encountered during clinical practice. These are comprehensive and include, but are not limited to, technical, diagnostic, demographic, and psychosocial factors. Conflicts of interest are acceptable within the Scenario Writing work group, provided that writers adhere to the NASS Disclosure Policy.
6. Scenario Review. A distinct group independently reviewed the scenarios, marking the primary deviation from the RAND methodology, and optimized the quality of scenario development. Feedback was given to the Scenario Writing work group for refinement and a final draft of scenarios was created. As part of the review process, the scenario document was scored by the review group as if they were raters to provide feedback and suggest improvements. Conflicts of interest are permissible if reviewers adhere to the NASS Disclosure Policy.
7. Literature Review Group. Concurrent to scenario writing and review, a literature review was conducted by the clinical practice guideline on this topic and used by the AUC work group. Members of the literature review group in CPG are required to be trained in evidence-analysis techniques. Literature review and completion of accompanying evidentiary tables is a critical component to the process. All relevant studies were summarized in evidentiary tables by the CPG work group which were then provided to the AUC raters to assist them with informed voting. All references and evidentiary tables can be found on the NASS website.
8. Rating Tool. A rating tool was developed in Excel based on the final modifiers, treatment modalities, and scenarios. This was used by the raters to help record responses. All data was tabulated electronically, and this was used subsequently for statistical analysis.
9. Rating. A multidisciplinary group of 13 raters was identified representing orthopedics, neurosurgery, physical medicine and rehabilitation, internal medicine, anesthesia pain management, rheumatology, radiology, and chiropractic specialists considered thought leaders in their respective field. There were a total of 7 nonoperative specialists and 6 surgeons. Three raters were part of the ongoing CPG development in this topic. Raters were not required to be trained in evidence analysis. They were required to have participated in the NASS disclosure process. The group was introduced to the scenarios and the rating method on a prerating conference call and the evidentiary tables were provided. Scenarios were to be rated based on appropriateness at large, and not necessarily relative to a rater’s individual practice. The raters each rated the scenarios independently and anonymously. The raters then met for a 2-day meeting to discuss the scenarios and participate in a second round of anonymous rating. This started with introductions and relevant disclosures. Deidentified scores from the first round of rating were compiled and presented to the group to facilitate discussion. Scenario content was clarified if needed. Consensus was not a goal and costs were not considered. Raters were directed to consider whether a procedure was reasonable, in general, for each scenario presented. Each treatment was evaluated independently and not in comparison to other treatment modalities. Raters combined evidence with personal experience and voted on the appropriateness of each scenario using a 1 through 9 scale. The votes were recorded, and the median used to determine the final score in line with RAND methodology. Scores of 1 to 3 indicate the procedure is rarely appropriate, 4 to 6 uncertain/maybe appropriate, and 7 to 9 appropriate.
10. Agreement. Final rating was dependent on the median score and the agreement (dispersion of ratings) amongst the panelists. Ratings were characterized as ‘with agreement’ when the inter-percentile range adjusted for symmetry of responses was greater than the inter-percentile range, as previously described in the RAND manual.1
11. Scoring. Based on the median score and agreement, final ratings were defined as: 1 to 3=Rarely appropriate with agreement · 4 to 6=Uncertain/Maybe Appropriate or Disagreement · 7 to 9=Appropriate with agreement
Construction of Scenarios:
Key modifiers were selected that most influenced treatment decisions (Table 3). From these modifiers, grids of scenarios were developed to describe a multitude of treatment options that were subsequently rated for appropriateness. These variables were considered for treatment options of medical therapy, radiation therapy, cement augmentation, reconstructive surgery, and ablation. This resulted in a total of 432 scenarios, with 5 treatment ratings per scenario, or 2160 total recommendations.
Table 3. Scenarios with their respective modifiers
Function
- Homebound ambulator
- Community ambulator
Pain
- Mechanical, VAS 0-6
- Mechanical, VAS 7-10
- Nonmechanical
Fracture morphology
- Complex, height loss <80%, intact posterior wall
- Complex, height loss <80%, non-intact posterior wall
- Complex, height loss >80%
Spinal stenosis
- No
- Yes, no change in sensory / motor / bladder function
- Yes, plus change in sensory / motor / bladder function
Radiosensitive
- Sensitive
- Insensitive
Prognosis / systemic
- Good
- Poor
SINS score
- Stable
- Unstable
Assumptions:
The purpose of this document was to evaluate the appropriateness of treatment for metastatic neoplastic vertebral fractures. Where medical/interventional/surgical treatment is mentioned, the document assumes that the type of treatment provided was within an acceptable community standard of care to the reader.
Statistical Analysis:
Each modifier was treated as a categorical variable and expressed as frequency and percentage. Fisher exact test was used to compare final appropriateness rating between modifier responses. Decision tree methodology was applied to identify the most important modifiers when deciding on treatment appropriateness. Decision trees were developed for radiation therapy, surgery, and cement augmentation. Modifiers that did not add to the accuracy of the classification were not included in the final decision tree. Relative modifier importance was computed for each decision tree (summing to one). To examine rater disagreement, a multivariable logistic regression model was fit to compute adjusted odds ratios of receiving a final rating of ‘Uncertain or Disagreement’ vs ‘Appropriate with Agreement,’ for scenarios with a median score of 7 to 9 for surgical treatment. All analyses were conducted using R 4.2.2., gtsummary package, and rpart package.