The Level of Evidence Pyramid: Indicating Levels of Evidence in Plastic and Reconstructive Surgery Articles

Abstract

The January 1, 2011, issue of Plastic and Reconstructive Surgery chronicled the official inauguration of a specialty-wide evidence-based medicine initiative for plastic surgery.1 A multispecialty group of journal editors and plastic surgery and related specialty society leaders along with evidence-based medicine experts met in Colorado Springs in August of 2010 to discuss how they could integrate evidence-based medicine into the basic daily fabric of plastic surgery. One of the key action points from that meeting was to have the scientific journals of the sponsoring societies begin to indicate the level of evidence grade for their articles. Beginning with this issue of Plastic and Reconstructive Surgery, the Journal inaugurates the listing of the level of evidence on all articles amenable to level of evidence grading. Listing of the level of evidence clinical question and level of evidence grade is a relatively straightforward yet highly visible way of promoting and advancing evidence-based medicine. Plastic and Reconstructive Surgery will do this in two ways. First, at the end of the article abstract, we will indicate the level of evidence question addressed by the article (diagnostic, therapeutic, or risk) and the level of evidence of evidence presented in the article (I through V) (Tables 1 through 3).2 Second, immediately to the left of the clinical question and level of evidence, we will place a visual icon of the level of evidence pyramid (Figs. 1 and 2), a symbol that also indicates the clinical question and level of evidence. Although in tandem they are somewhat redundant, together the two elements provide quickly assimilated visual cues as to the overall strength of the data presented in the article.Table 1: American Society of Plastic Surgeons Rating Levels of Evidence and Grading Recommendations: Evidence Rating Scale for Therapeutic StudiesTable 2: American Society of Plastic Surgeons Rating Levels of Evidence and Grading Recommendations: Evidence Rating Scale for Diagnostic StudiesTable 3: American Society of Plastic Surgeons Rating Levels of Evidence and Grading Recommendations: Evidence Rating Scale for Prognostic/Risk StudiesFig. 1.: The level of evidence pyramid, showing level of evidence (I through V), and clinical question addressed by the article. (Left) Diagnostic clinical question addressed, with a level of evidence of II. (Center) Therapeutic clinical question addressed, with a level of evidence of III. (Right) Risk clinical question addressed, with a level of evidence of II.Fig. 2.: Representative title page of an article with the new level of evidence grading in place. Note that the clinical question/level of evidence is indicated at the bottom of the structured abstract. The level of evidence pyramid indicates the same information to the left of the abstract.LEVEL OF EVIDENCE GRADING: WHAT IT MEANS In publishing the level of evidence of articles in Plastic and Reconstructive Surgery, we endeavor to promote a larger overall focus on evidence-based medicine, the systematic, deliberate, and scientific methodology that aims to improve the overall quality of clinical care and patient outcomes and safety. Multiple level of evidence rating scales exist, and although there are some differences among the various scales, most are very similar to the American Society of Plastic Surgeons (ASPS) Levels of Evidence Rating Scale that Plastic and Reconstructive Surgery uses (Table 1). The highest level of evidence is level I, representing high-quality randomized controlled trials; the lowest level of evidence is level V, representing expert opinion. One long-term goal of the overall evidence-based medicine initiative is to elevate the level of evidence of Plastic and Reconstructive Surgery articles, which will take place as a lengthy (multiyear), deliberate process through training and education. The focus on level of evidence in the Journal's articles is to help authors, reviewers, editors, and readers to critically evaluate the level of evidence of articles, which will eventually lead to papers with increasingly higher levels of evidence. Many concerned authors have asked us, with our heightened focus on evidence-based medicine and the level of evidence of papers, whether Plastic and Reconstructive Surgery will no longer accept papers with lower levels of evidence. Be assured that we have no intention of limiting manuscript submissions based on the level of evidence of the data presented in the paper. If Plastic and Reconstructive Surgery (or any plastic surgery journal, for that matter) would accept only articles with level of evidence I or II data, the Cosmetic section and 90 percent of all other contributions would be eliminated. Using that criterion, many of the Editor-in-Chief's own contributions would be turned down, seeing that they are level IV or V! Well-written articles of all levels of evidence have an important place in plastic surgery. Individual case series, case reports, and expert opinion (levels III through V) can address some subtleties of surgical technique or personal perspective that are valuable to the practicing surgeon but not currently amenable to prospective, controlled, randomized trials. However, certain important clinical decisions (like whether or not to give chemoprophylaxis in a certain patient population) can only be definitively answered by controlled randomized trials and higher levels of evidence. Having the right balance is critical for optimal education, and Plastic and Reconstructive Surgery will always encourage manuscripts with all levels of evidence, from I through V. What we are implementing this month is that all papers amenable to level of evidence grading begin to indicate their level of evidence, so that readers can quickly see the level and evaluate the paper accordingly. Our goal is to help educate and encourage authors to look at their data and begin to develop and publish studies with increasingly higher levels of evidence. However, we will always welcome and publish well-written, well-conducted studies with levels of evidence of III through V. DETERMINING THE LEVEL OF EVIDENCE FOR PLASTIC AND RECONSTRUCTIVE SURGERY ARTICLES: THE PROCESS Only Certain Manuscripts Are Amenable to Level of Evidence Grading Approximately 40 percent of the articles in Plastic and Reconstructive Surgery are not ratable.3 A rule of thumb to help exclude articles that cannot be rated for level of evidence is as follows: Animal studies Cadaver studies Basic science studies Review articles Instructional course lectures CME courses Editorials Correspondence As far as what is or is not ratable, the standard is to exclude basic science, bench work, and animal and cadaveric studies because the information gained from these studies is not something that can be applied directly to patient treatment decisions. The U.S. Food and Drug Administration requirements can be helpful in thinking about level of evidence grading: first, there are the preclinical laboratory and animal studies (which are not gradable); then, there are the human clinical trials (which are gradable). As a potential author, you determine that your manuscript is amenable to level of evidence grading. What is the next step? New Level of Evidence Instructions for Authors—New Level of Evidence Elements and Resources As of July 1, 2011, all manuscripts amenable to level of evidence grading that are submitted for consideration to Plastic and Reconstructive Surgery need to indicate the level of evidence clinical question and level of evidence grade in the manuscript abstract. In instituting this new submission requirement, we offer authors the following resources to help them evaluate their data, studies, and manuscripts: Plastic and Reconstructive Surgery Information for Authors (www.editorialmanager.com/prs/). ASPS level of evidence grading recommendations table (Table 1). Plastic and Reconstructive Surgery evidence-based medicine article collections. Evidence-Based Medicine “How-To Articles” collection (http://journals.lww.com/plasreconsurg/pages/collectiondetails.aspx?TopicalCollectionId=24). Evidence-Based Medicine “Outcomes” collection (http://journals.lww.com/plasreconsurg/pages/collectiondetails.aspx?TopicalCollectionId=19). Author tutorial: ASPS “Evidence Based Medicine and the Critical Appraisal Process” (www.PRSJournal.com, http://www.plasticsurgery.org, and www.editorialmanager.com/prs). Reviewer tutorial: ASPS “Reviewing Concepts in Study Design and Critical Appraisal” (www.PRSJournal.com, http://www.plasticsurgery.org/, and www.editorialmanager.com/prs/). See the companion article, “The Levels of Evidence and Their Role in Evidence-Based Medicine,” in this issue.4 In addition to those resources now available on the Plastic and Reconstructive Surgery, enkwell, and ASPS websites, there will be evidence-based medicine and level of evidence training courses at future ASPS and American Society for Aesthetic Plastic Surgery Annual Meetings for both authors and reviewers. These training courses, which we anticipate will be made available on an annual basis, will provide live, hands-on training in evidence-based medicine methodologies and level of evidence evaluation. Using the above resources, we ask authors to make their best estimation of the level of evidence for their manuscript at the point of manuscript submission. Level of Evidence Grading of Submitted and Accepted Manuscripts Once submitted, manuscripts are reviewed. Plastic and Reconstructive Surgery is training its reviewer panels on how to determine level of evidence clinical question and grading. As part of the review process, we will ask our reviewers to indicate their assessment of the level of evidence for the papers they review. After manuscripts have been reviewed, revised, and accepted for publication, they will be sent to independent evidence-based medicine and level of evidence experts, who will rate the manuscripts for clinical question and level of evidence grade. These experts will make the final determination of the level of evidence of all accepted papers, and their decisions will be reflected in the published level of evidence of the articles. For those papers that are not gradable, we will leave the level of evidence grade off of the published abstract. THE LEVEL OF EVIDENCE INITIATIVE: THE GOAL To reach a goal, you need to have certain awareness of the elements needed to obtain it. Publishing the level of evidence of articles is simply a way to make authors, reviewers, and readers aware that evidence-based medicine and level of evidence are important to Plastic and Reconstructive Surgery, and to plastic surgeons as a group. We think that awareness of level of evidence will help surgeons make better informed decisions regarding the quality of the data in the articles they read, which will in turn lead to a gradual elevation in the overall level of evidence of the articles in the Journal. That awareness of the literature will correspondingly lead to heightened awareness in the individual surgeon's own practice, enabling him or her to make better decisions, improve the quality of care, and enhance patient safety and outcomes. With such goals in mind, we encourage you to download the level of evidence tutorials, attend the evidence-based medicine and level of evidence training sessions, and submit your manuscripts to the Journal. Our specialty and patients will all benefit from such effort. ACKNOWLEDGMENTS The authors thank DeLaine Schmitz, Karie Rosolowski, and Jennifer Swanson of the ASPS Health Policy and Advocacy Department for their assistance, research, and development of evidence-based medicine training materials. They acknowledge and thank Felmont F. Eaves III, M.D., for the original concept of the level of evidence pyramid, and Angela Burch, Coordinator, Graphic Design, in the Plastic and Reconstructive Surgery editorial office for refining the design of the level of evidence pyramid.