Art and Science of Guideline Formation




Summary of Key Points





  • Clinical practice guidelines have become an integral part of the practice of medicine. They are here to stay and will continue to inform clinical practice.



  • Important resources exist to help with the formation of these guidelines and to provide an archive of existing guidelines and those in the process of being made.



  • They are also used to for the assessment of current best practices, guidance for future research, and defense of unpopular yet effective treatment strategies.



  • This chapter explores the process of clinical guideline formation, from when an author group is formed to the publication of the recommendations.



  • Clinical practice guidelines need to be reviewed in a timely manner so as to keep pace with emerging evidence. A method of evaluating the impact of clinical practice guidelines should always be formulated.



Clinical practice guidelines have become an integral part of the practice of medicine. They are meant to be used by physicians as resources to consider when making treatment decisions for individual patients. They are also frequently used by various organizations for policy and payment decisions. In the United States, the National Guidelines Clearing house (NGC) provides a guideline index and archive and tracks those in progress. Important guideline resources from this site include the Guideline Elements Model (GEM), which is an XML-based guideline document model that can store and organize the heterogeneous information contained in practice guidelines. This is intended to facilitate translation of natural language guideline documents into a format that can be processed by computers. This document is generalizable and is intended to be used throughout the entire guideline life cycle to model information pertaining to guideline development, dissemination, implementation, and maintenance. Information at both high and low levels of abstraction can be accommodated.


GEM II is constructed as a hierarchy of more than 100 elements with 10 major branches: Identity, Developer, Purpose, Intended Audience, Target Population, Method of Development, Testing, Revision Plan, Implementation Plan, and Knowledge Components. This model represents an international standard for the representation of practice guidelines in XML format and has become an American Society for Testing and Materials (ASTM) standard.


As of December 2014, 2603 sets of clinical guidelines are listed on the NGC, with 111 additional guideline sets registered as “in progress” ( www.guideline.gov ). One hundred and seventy-four guideline sets in this one database focus on disorders of the spine. Only 35 of these were produced by organized spine surgery, sponsored by either the American Association of Neurological Surgeons/Congress of Neurological Surgeons (AANS/CNS) Section on Disorders of the Spine or the North American Spine Society. There were 21 publications in 2013 alone. These sets do not include myriad “technology assessments” commissioned by third-party payers, nor do they include a multitude of guidelines, evidence-based reviews, evidence-informed consensus statements, or other similarly titled systematic literature reviews published and disbursed outside of the NGC system. Clinical practice guidelines are here to stay and have proved to be important for the assessment of current best practices, guidance for future research, and defense of unpopular yet effective treatment strategies. This chapter describes how guidelines are created in both the ideal situation and in the real world.




Author Group


One of the most useful tools for learning about evidence-based medicine, guidelines, and the application of guidelines to the real world is a small text by David Sackett and the McMaster University group called Evidence Based Medicine. We refer to this text several times in this chapter when discussing how to rate evidence and how to apply evidence to clinical situations. In the chapter devoted to a discussion of the creation of clinical practice guidelines, Dr. Sackett offers the reader the following advice:



We hope … that you see how doubly dumb it is for one or a small group of local clinicians to try and create the evidence component of a guideline all by themselves. Not only are we ill equipped and inadequately resourced for the task, but by taking it on we steal energy away from … our real expertise. … This chapter closes with the admonition to frontline clinicians: when it comes to lending a hand with guideline development, work as a “B-keeper*” not a meta-analyst.


Despite this warning, it is absolutely critical that physicians with clinical expertise participate in the formation of clinical practice guidelines. Although epidemiologic support is necessary for the analysis of study design, clinical data cannot be accurately interpreted and the translation of data to recommendation cannot be made without an understanding of the clinical significance of the data. This understanding does not come from textbooks. A more reasonable interpretation of Sackett’s statement is that it is not efficient or desirable to have individual groups spend the resources to develop practice guidelines at a local level. It makes more sense to have guidelines produced at a national level and leave the interpretation of those guidelines to the local experts. A series of review articles published in the Journal of the American Medical Association by the same author group offers detailed explanations of many of the concepts to be discussed in this chapter. The level of detail is inappropriate for this particular review, but the reader is encouraged to use these as references for further inquiry.


High-quality guidelines ideally have an author group that consists of a multidisciplinary panel of recognized experts in the disease process studied. Depending on the disorder studied, multidisciplinary may mean two related specialties (e.g., orthopedics and neurosurgery for cervical spine trauma—no other specialties regularly deal with this issue) or perhaps members drawn from five or six disparate specialties (e.g., the American College of Radiology imaging appropriateness criteria, in which multiple specialties treat common clinical scenarios such as low back pain). Epidemiologic support is also crucial, and having an epidemiologist on the author panel is an ideal solution. All panel members should have some understanding of basic statistical methods and access to a statistician.


Conflict of interest is an important issue in the formation of a guidelines author group. Disclosure of such conflicts is the first step in managing conflicts, and the organizing body, be it a medical society, university work group, or insurance carrier, must decide how to manage or resolve the conflict. In some situations, compromises are necessary in order to garner sufficient topical expertise. In most situations, however, author groups can be constructed and organized to mitigate the possibility of industry-related conflicts. It is our opinion that industry-sponsored “study groups” are an inappropriate source for clinical practice guidelines because the membership of and strategic direction of these panels may be easily influenced by the sponsoring body. Similarly, technology assessments produced by centers that are funded largely by third-party payers cannot be considered practice guidelines because they are paid for by entities primarily desiring to limit economic exposure as opposed to evaluating clinical efficacy. Furthermore, these panels notoriously lack relevant physician input and tend to place a higher value on study design and author interpretation of data than on common sense and clinical fact. (For example, go to www.ecri.org and review its assessment of “decompressive procedures for lumbosacral pain.” You will note that the author group contained only one physician, an Emergency Care Research Institute [ECRI] employee who practices internal medicine. No spine surgeon, physical therapist, rehabilitation physician, or other specialist input was solicited, and the topic is clearly ridiculous to anyone who regularly cares for these patients—decompression is not done as a treatment for low back pain, it is done for radiculopathy or symptomatic stenosis.)


Those in the field of organized spine surgery, including the American Association of Neurological Surgeons and Congress of Neurological Surgeons Joint Section on Disorders of the Spine (Spine Section) and the North American Spine Society (NASS), have been active in guidelines development. The first significant product developed using modern evidence-based review techniques was the set of clinical practice guidelines dealing with cervical spine and spinal cord injury. The author group was recruited by Mark Hadley and consisted exclusively of neurosurgeons, both because of the funding agency (the spine section) and because of relative inexperience in guidelines formation. The group included general neurosurgeons, pediatric neurosurgeons, and neurosurgical spine specialists. Beverly Walters, a neurosurgeon who had trained in clinical epidemiology at McMaster University, served as the epidemiologist. Each of the authors was employed at an academic center and had the support of local expertise in library science and statistics if necessary. The authors were tutored in evidence-based medicine techniques during 4-week-long sessions in order to solidify their ability to interpret the medical literature.


These guidelines were unique in the spine world and were qualitatively different from the various consensus-based guidelines that had been published previously (e.g., the NASS Low Back Pain Treatment Guidelines published in 1999). Because they applied to a relatively small patient population and because they were originally published as a supplement to Neurosurgery, a journal with virtually no penetrance into emergency medicine or orthopedics, they did not receive immediate notoriety. With the exception of chapters dealing with the administration of steroids and the safety of traction reduction without magnetic resonance imaging (MRI), few recommendations were considered controversial.


The AANS/CNS spine section was then charged with organizing a set of guidelines dealing with the topic of lumbar fusion. The section actively sought input from orthopedic surgeons and physical medicine specialists in addition to neurosurgeons. Beverly Walters agreed to continue on in an advisory capacity, and several members of the cervical spine injury group, including Mark Hadley, were recruited to lend their expertise to the project. Because of the novelty of the process and the time commitment (a month away from home in addition to the time spent working on the project), it was difficult to recruit non-neurosurgeons. After being turned down four times by well-known orthopedic surgeons, the chairman of the NASS clinical care council, Bill Watters, volunteered himself and helped recruit Jeff Wang from the University of California at Los Angeles to be the orthopedic representatives on the panel. We were unable to recruit a physical medicine and rehabilitation physician to the panel, despite overtures to both local and national contacts.


Since the publication of the lumbar fusion guidelines, the visibility of guidelines formation has increased substantially. The economic effect of the recommendations, the timeliness of the publication in relationship to a political and popular examination of lumbar fusion, a more easily searchable publication format, and inclusion in the NGC substantially improved penetrance of these guidelines compared with that for the cervical spine injury guidelines. Vocal objections to the formation of clinical practice guidelines by “grassroots” neurosurgeons (via the Council of State Neurosurgical Societies) and others focused attention on the process. The use of guidelines to support continued patient access to spine surgeons in Washington State and in several national insurance plans by a coalition of national organizations, including the AANS, CNS, NASS, American Association of Orthopedic Surgeons (AAOS), and Scoliosis Research Society (SRS), further highlighted the importance of such activities.


Subsequent guidelines efforts sponsored by the spine section or NASS have uniformly included broad representation of relevant clinical specialties. The year 2013 saw an additional 21 guidelines published as indexed in the NGC. Both organizations require intensive training of author panel members. The AANS/CNS guidelines committee continues to rely on a didactic series of lectures developed by Beverly Walters and moderated by the chairs of the guidelines committee (currently Mark Linskey and Tim Ryken). The NASS has employed an online training module combined with on-the-job training. Bill Watters and Chris Bono have effectively used the NASS infrastructure to develop a primarily web-based mechanism for guidelines formation. Both organizations have now developed a cadre of well-trained clinician authors, both support multidisciplinary guidelines formation, and both support consultation with professional epidemiologists as needed.




Question Formation


Once an author group is formed, a set of questions is developed. The questions asked are a very important determinant of the utility of the ultimate guideline document. Questions need to be both relevant and answerable. A question such as “What is the best treatment for low back pain?” is unanswerable. Patients with low back pain are a heterogeneous population. Back pain may be caused by muscular strain, traumatic injury, degeneration of the intervertebral disc, or spinal tumors. It may be a symptom of renal calculi, dissecting aortic aneurysm, or a somatization disorder. There is, therefore, no one best treatment for back pain, and attempting to answer such a question is a frustrating and fruitless endeavor. A better question would be “In a patient with recalcitrant low back pain and neurogenic claudication due to spondylolisthesis and stenosis, does surgical intervention improve outcomes compared with the natural history of the disease?” Here, the patient population is well defined and the treatment modalities are well described, allowing a meaningful review of the medical literature. During the literature search, it may become apparent that multiple surgical interventions are employed, resulting in the parsing of the question into subcomponents related to individual surgical techniques.




Literature Search


The availability of computerized search engines has greatly simplified the ability to identify potentially useful references. Most guidelines groups use two different search engines and databases to ensure a thorough search. Familiarity with mesh headings or consultation with a librarian is very useful in creating an effective search that will not be overly inclusive. Unfortunately, the era of electronic publishing has greatly increased the number of potentially useful references (when just the title and abstract are available for initial screening), and it is not uncommon to obtain several hundred or even several thousand references that require individual review. Several strategies can be used to speed this process. First of all, if sufficient high-quality evidence, such as several concordant randomized trials, exists, lower-quality evidence may be ignored except as background information. For example, about 7 billion papers deal with the use of microdiscectomy for lumbar radiculopathy (okay, an exaggeration). Of these papers, 99.9% are case reports, small case series, technical notes, or historic anecdotes. There are a few large cohort studies with admittedly fatal flaws. Fortunately, several attempted randomized studies have been published that provide higher-quality evidence than all of the other papers. Instead of spending months describing each case series, we can focus our review on a detailed analysis of the higher-quality papers and simply summarize the findings of the various case series. If the primary references are flawed, however, then we must incorporate the lower-quality evidence into the analysis.


Another way to speed up the literature search and review is to set minimum acceptable criteria for inclusion in the database. This is the strategy used by the Cochrane group, which only considers randomized clinical trials (RCTs) as evidence worthy of review. Although this strategy certainly speeds up the review process, many relevant questions in the surgical realm are not particularly amendable to study via RCT. If the Cochrane criteria were applied to the surgical management of symptomatic intracranial extradural hematomas, the conclusion would necessarily be that there is no evidence to support the evacuation of such hematomas. No RCT has ever been performed on this patient population. Although academically pure, the adherence to such high standards breaks down in the trenches. A very humorous article in the British Medical Journal pointed out that because skydiving with a parachute was associated with occasional fatality, and that survival following falling out of plane with no or a malfunctioning parachute had been described, in the absence of a randomized trial, it must be concluded that there is no evidence to support the use of a parachute to increase survival when jumping out of an airplane.

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Feb 12, 2019 | Posted by in NEUROSURGERY | Comments Off on Art and Science of Guideline Formation

Full access? Get Clinical Tree

Get Clinical Tree app for offline access