In these columns, I try to illustrate the practical application of evidence-based veterinary medicine (EBVM) to the kind of real-world clinical problems I encounter as a general practitioner in companion animal medicine. My goals are both to provide useful information on specific topics and also to demonstrate EBVM is not just a tool for researchers or ivory-tower academics, but something that can make life easier and medicine more effective and efficient for those of us in private practice.
While most general practice veterinarians have positive attitudes toward EBVM in general, many are unsure how to implement it in their daily work. Finding and critically evaluating research evidence is difficult and time-consuming, and the quantity and quality of evidence available is usually less optimal. However, there are a number of resources that can help.
Physicians rarely search the primary research literature when looking into best practices for treating a specific patient. Evidence summaries and clinical practice guidelines (CPGs) are abundant in human medicine, and doctors are taught to use such synthetic resources as a faster and more reliable alternative to trying to keep up with all the latest research. Veterinarians, however, have fewer such resources, just as we have less research evidence on which to rely. Yet, there is a growing number of EBVM tools those of us in primary care practice can use to help make evidence-based clinical decisions.
Clinical practice guidelines
CPGs are one of the most convenient tools for incorporating research evidence into clinical practice. These are typically guidelines for best practices in diagnosis and management of specific clinical problems. A good CPG defines the clinical problem and patient population clearly, so the clinician can assess whether or not the information is applicable to a specific patient. Such a guideline should also cover a comprehensive collection of relevant diagnostic and treatment interventions, and provide an assessment of the strength of evidence for every recommendation. Because evidence changes over time, reliable guidelines must be updated regularly.
An excellent example of an evidence-based CPG is produced by the Reassessment Campaign on Veterinary Resuscitation (RECOVER). These invaluable CPR guidelines were produced through a rigorous and transparent process of critical evaluation of published research evidence. The final guidelines were published in 2012 and made available for free.1
The RECOVER CPGs provided a clear set of recommendations for diagnosing and managing cardiopulmonary arrest in small animals and identified the strength of evidence for each. RECOVER went even further, providing a variety of materials to support implementation of the guidelines and setting up a system for training and certifying veterinarians and veterinary technicians in basic and advanced life support techniques. The organizers planned to provide regular evidence reviews and updates to the guidelines, though this has not yet been accomplished.
RECOVER provides a model for how evidence-based CPGs can transform clinical practice around a specific medical problem. Not all CPGs, however, are as reliable because they do not share the methodological rigor or transparency of the RECOVER guideline development process. Some CPGs are simply published expressions of the opinions or practices of the groups of individuals who produce them. Such guidelines may be convenient and useful, but they are not truly evidence-based. Clinicians should consider the methods used to develop specific guidelines and be more skeptical of recommendations that do not clearly and explicitly identify the strengths and limitations of the research evidence upon which they are based.
Systematic reviews (SRs)
Another useful tool that can help busy clinicians find research evidence to guide their practice is the systematic review. This is a published summary and critical appraisal of the research evidence concerning a defined topic, such as a disease or treatment. While SRs do not provide specific recommendations for clinical practice, they offer a summary of the relevant research literature with an assessment of the strength of this evidence. Individual studies inevitably have limitations and some degree of error or uncontrolled bias, so a systematic review provides a more accurate assessment of the overall balance of evidence.
Though there are fewer SRs in veterinary medicine than in human medicine, the number is growing rapidly. It is now easy to find systematic review in the veterinary field through a database produced by the Centre for Evidence-based Veterinary Medicine (CeVM) at the University of Nottingham. VetSrev is a convenient, free resource listing all SRs published in veterinary medicine. Getting access to the reviews themselves can be more challenging, since not all are freely available. However, clinicians can often get copies of SRs through online resources such as those listed at the end of this article or through the closest veterinary college library.
Just as not all CPGs are reliable or evidence-based, it is important to be aware that not all literature reviews are systematic reviews. Narrative reviews are a more common type of publication in which individual authors provide a summary of research evidence without following the strict methodology for identifying and appraising the literature that characterizes systematic reviews. While narrative reviews can be useful, they reflect the perspective and biases of their authors, and they often exclude studies or interpret the available evidence in ways that conform to these biases.
Critically appraised topics
Critically appraised topics (CATs) are similar to SRs in that they summarize the research literature on a specific topic, but they are typically much shorter and more narrowly focused. For example, if a clinician is interested in the potential use of glucosamine supplements for a canine patient with arthritis, they might find some relevant information within “A systematic review of efficacy of nutraceuticals to alleviate clinical signs of osteoarthritis.”2 However, a more narrowly focused CAT might be easier to use, such as one that reviews evidence answering the question, “In dogs with osteoarthritis, is a glucosamine and chondroitin supplement vs. carprofen better at reducing the clinical signs of osteoarthritis?”3
While CATS are shorter and more focused than SRs and do include systematic, transparent identification and appraisal of research evidence, they are less comprehensive and less rigorous than systematic reviews. It may be harder to find a CAT addressing the specific question a clinician has regarding an individual patient, and it is easier for individual bias to influence the conclusions of this type of review. CATs are produced and made available by a variety of organizations, such as the Best Bets for Vets site run by CeVM, and the Knowledge Summaries produced by the Royal College of Veterinary Surgeons (RCVS) Knowledge Group and published in the open access online journal, Veterinary Evidence.
The following are some places clinicians can find guidelines and evidence reviews. As always, each should be evaluated critically to assess the reliability of their methods and conclusions, and the applicability to individual patients. Evidence-based medicine provides practitioners with useful tools, but it also requires active engagement and critical thinking from clinicians to judge the quality and utility of research evidence and to adapt this evidence to the needs of a specific practice setting and patients.
- The RECOVER Initiative: A resource for guidelines and training in small animal CPR (recoverinitiative.org)
- VeSRev: A database of veterinary systematic reviews (webapps.nottingham.ac.uk/refbase)
- BestBets for Vets: A collection of critically appraised topics (bestbetsforvets.org)
- RCVS EBVM Site: A large collection of EBVM resources, including CATs and an open-access online journal (bit.ly/2NPmZgA)
- American Animal Hospital Association’s (AAHA’s) CPGs: Clinical practice guidelines that are useful though often based predominantly on expert opinion and not as methodologically rigorous as the RECOVER CPG (bit.ly/3gmsmjr)
- American Association of Feline Practitioners (AAFP) CPGs: Clinical practice guidelines relating to feline medicine. These are also predominantly based on expert opinion (bit.ly/2NTzU1e)
- American College of Veterinary Internal Medicine (ACVIM) CPGs: A collection of consensus statements that review and appraise the evidence and suggest best practices for management clinical conditions within the area of internal medicine (bit.ly/2VGd8OE)
Brennen McKenzie, MA, MSc, VMD, cVMA, discovered evidence-based veterinary medicine after attending the University of Pennsylvania School of Veterinary Medicine and working as a small animal general practice veterinarian. He has served as president of the Evidence-Based Veterinary Medicine Association and reaches out to the public through his SkeptVet blog, the Science-Based Medicine blog, and more. He is certified in medical acupuncture for veterinarians. Columnists’ opinions do not necessarily reflect those of Veterinary Practice News.
1 Fletcher D, Boller M, Brainard B, et al. RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR. Part 7: Clinical Guidelines. J Vet Emerg Crit Care. 2012;22 Suppl 1. doi:10.1111/J.1476-4431.2012.00757.X
2 Vandeweerd J-M, Coisnon C, Clegg P, et al. Systematic review of efficacy of nutraceuticals to alleviate clinical signs of osteoarthritis. J Vet Intern Med. 26(3):448-456. doi:10.1111/j.1939-
3 Belshaw Z, Brennan M. Nutraceuticals versus carprofen in dogs with osteoarthritis – BestBETS for Vets. https://bestbetsforvets.org/bet/521. Published 2018. Accessed June 12, 2020.