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The Argument for Evidence-Based Medicine and the AAN's Most Sought After Resource

Avitzur, Orly MD

doi: 10.1097/01.NT.0000316149.35450.6a

Dr. Avitzur, a neurologist in private practice in Tarrytown, NY, holds academic appointments at Yale University School of Medicine and New York Medical College. She is also the editor-in-chief of the AAN Web site,, and chair of the AAN Practice Management and Technology Subcommittee.

Seldom has the power of clinical guidelines been more vividly demonstrated than in the rancorous response of Lyme disease activists to the November 2006 guidelines of the Infectious Diseases Society of America (IDSA). The IDSA guidelines stated that “antibiotic therapy has not proven to be useful and is not recommended for patients with chronic subjective symptoms after administration of recommended treatment regimens for Lyme disease.” Hundreds of patients rallied outside of the Westchester County Medical Center office of the document's lead author, Gary P. Wormser, MD, chief of the division of infectious disease at the hospital.

“Protesters from as far away as California and Texas waved a sea of neon-green signs at passing cars at the intersection of Woods and Grasslands roads, some of which personally mocked the doctor with messages like, ‘Wormser Lies…Patients Die’” reported the Dec. 1, 2006 issue of the Rockland/Westchester County, NY, newspaper The Journal News. Protestors argued that the guidelines would limit treatment options for patients by causing insurance companies to deny reimbursement for long-term intravenous antibiotic therapy and by influencing physicians.





So five months later when the AAN released its guidelines on the treatment of nervous system Lyme disease and post-Lyme syndrome — stating that there is no compelling evidence that prolonged treatment with antibiotics has any beneficial effect in post-Lyme syndrome — one would think that its lead author, John J. Halperin, MD, would have had cause for trepidation. Instead, he feels more strongly than ever about the utility and need for clinical guidelines.

“We all fall victim to the temptation of basing treatment on what we last saw with our own eyes,” said Dr. Halperin, who believes that the activists' response was based on the natural human tendency to form opinion based on anecdotal observation. “But hopefully, with the implementation of evidence-based medicine, our profession has transcended this,” he added.

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It is also the reason that organizations need to follow a rigorous, conscientious process for developing clinical guidelines, Dr. Halperin said. “This process is particularly well-defined at the AAN,” Dr. Halperin observed, adding that he relies on guidelines in many other areas of his practice.

“I just don't have the time to read 300 articles on a given condition, distill them to 60 for intensive review, and arrive at rational conclusions.” The description exemplifies the exhaustive methodology, which ultimately led to the creation of the Lyme disease guidelines and is indeed typical of the work done to develop most guidelines at the Academy.

Allan Krumholz, MD, director of the University of Maryland Epilepsy Center, served as chair of a committee that developed the practice parameter on the diagnosis and evaluation of an apparent unprovoked first seizure in adults. He described the rigorous details of the process, which began with an evidence-based appraisal and systematic review of the literature published in English — from which 793 articles were obtained in abstract form and 157 articles were selected for review of the full-text article. Two committee members accepted or rejected articles using predetermined inclusion and exclusion criteria. The criteria, which are determined by each panel, vary for each guideline, based on the clinical question. For example, the panel led by Dr. Krumholz excluded animal studies, and those that dealt with patients with established or chronic epilepsy or acute provoked seizures, but it included studies that included at least 10 patients with a first seizure or first diagnosis of epilepsy, as well as studies dealing with diagnostic interventions, among other criteria.

When reviewers did not agree, a third reviewer cast the determining vote. Ultimately, 39 papers were selected as acceptable. Of an additional 33 studies identified from review articles and other sources from the same time period, 14 were selected for inclusion.

Each accepted study was abstracted by one investigator and agreed to by a second. All eligible papers were scored on features pertinent to study design, execution, and reporting. The quality of evidence was graded using a four-tiered classification scheme — criteria for which also vary depending on whether the clinical question is therapeutic, diagnostic, or prognostic. The top two tiers of evidence — class 1 and class 2 — formed the basis of the committee's recommendations.



In 2006, the AAN published the 100th guideline. On average, the AAN publishes eight guidelines annually. Four are currently in press: therapies for benign paroxysmal positional vertigo and use of botulinum toxin for the treatment of autonomic disorders, as well as pain, movement disorders, and spasticity. Two AAN committees oversee the development of evidence-based practice guidelines called practice parameters and technology assessments: the Quality Standards Subcommittee and the Technology and Therapeutics Subcommittee.

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Gary S. Gronseth, MD, co-chair of the Quality Standards Subcommittee, has helped create guidelines for EEG in headache, thymectomy for myasthenia gravis (MG), evoked potentials for multiple sclerosis, patent foramen ovale, and botulinum toxin for headache, among others. “The guidelines provide a succinct, transparent review of the evidence concerning controversial topics,” Dr. Gronseth said.

Nevertheless, some neurologists who view guidelines with skepticism, Janis Miyasaki, MD, co-chair of the AAN Technology and Therapeutics Subcommittee, said: “Some see them as potential legal swords against practitioners (for non-adherence or for adherence), as covert attempts by pharmaceutical companies to include their own products in standards of care, or as attacks on experience and clinical acumen to direct practice. But in reality, physicians have always practiced evidence-based medicine; now, we must do so in an explicit, transparent, and defensible manner.”

More often than not, Dr. Gronseth said, the guidelines provide information about the quality of the best evidence informing a topic, rather than dictating practice. After reading the guidelines on thymectomy for the treatment of MG, for example, a neurologist would understand that the effectiveness of the surgery is far from established, Dr. Gronseth explained. “Armed with this information a physician, can inform the myasthenia patient of the uncertainty of its benefit and come to a decision based on what is known: that both considering thymectomy and not considering thymectomy are reasonable alternatives.”

Likewise, Dr. Gronseth advised that after reading the guideline on starting dopaminergic therapy for Parkinson disease, the neurologist would learn that we do not know which is best: starting levodopa or a dopamine agonist first. “The choice involves a trade-off between better motor control with levodopa versus a higher risk of dyskinesias with levodopa.”

“Unfortunately, some neurologists still believe that recommendations to use certain drugs are influenced by pharmaceutical companies, and as a response, prescribe only generic drugs,” said, Rajesh Pahwa, MD, director of the Parkinson Disease (PD) and Movement Disorder Center at the University of Kansas Medical Center, who led the panel that wrote the guideline for advanced PD. “Fifty members review the process to eliminate any bias that may be present,” he said. “In the current atmosphere of pharmaceutical influence on treatment, guidelines are based on evidence-based data rather than promotion of a drug.”

“The guidelines are written and reviewed by passionate volunteers who devote countless hours of their time to try to make sense of the neurologic literature,” Dr. Gronseth said, pointing out that the AAN dedicates considerable staff and financial resources to this effort. “The Academy and volunteers do this work for one reason — to help the practicing neurologist help patients.”

©2008 American Academy of Neurology