Any systematic deviation of research results from the true state of the subject being studied. Most often, bias is an unintentional result of how research studies are designed and conducted.
Clinical Practice Guideline: Management recommendations for specific health conditions. To be considered evidence based, guidelines must be produced using systematic methods to reduce bias.
Critically Appraised Topic: A brief summary and appraisal of the evidence concerning a narrow clinical topic which resembling a systematic review but is shorter and less comprehensive.
Primary Literature: Published reports of original research studies.
Synthetic Literature: Published summaries and critical analyses of primary research studies.
Systematic Review: A comprehensive summary and critical appraisal of primary research studies conducted according to established procedures for minimizing bias.
2.1.3 What Is EBVM?
Evidence‐based veterinary medicine is a comprehensive system for generating reliable scientific evidence and getting it to those who need it in clinical practice and then integrating this evidence into clinical decision making.
In the research environment, EBVM guides the design and conduct of scientific studies to minimize bias and ensure the data generated are reliable. This element of EBVM is useful for researchers, but it is also critical for clinicians who use scientific research to inform their patient care.
EBVM tools also support the reporting of research studies in a manner that minimizes bias and ensures the reliability and utility of research evidence for the end‐user, the veterinary clinician. EBVM also facilitates the dissemination of research evidence, through reporting guidelines and support for open‐access publishing, to get evidence to those who need it to make healthcare decisions.
Synthetic literature sources, such as systematic reviews, critically appraised topics, and clinical practice guidelines, are practical ways of translating research into useable information for clinicians. EBVM provides standards for generating these resources and making them accessible to veterinarians in practice. This reduces the time and effort needed to find and critically evaluate needed information in the scientific literature.
Finally, EBVM includes techniques and training for clinicians to help identify their information needs and then find relevant and useful evidence. Knowing what information is most important for assessing risk and guiding treatment, and knowing how to find this information and how to judge whether it is reliable and applicable to a given patient, is a key part of providing consistent, effective pet‐specific care.
2.1.4 Why Do We Need EBVM?
In the absence of EBVM practices, clinicians typically base their decisions on sources of evidence other than scientific research, especially the opinions of colleagues and perceived experts. When clinicians do use research findings to guide their practice, this involves an informal, haphazard consultation of textbooks, journal articles and other sources, often without critical assessment for bias. Veterinarians often rely most heavily on their own experience and intuition in making patient care decisions. This collection of strategies is referred to as opinion‐based medicine.
Unfortunately, personal experience, even that of highly trained and experienced individuals, is subject to many cognitive biases and other sources of error that make it less reliable than is generally believed. Such biases lead to erroneous conclusions which undermine the safety and efficacy of medical interventions. The success of modern, science‐based medicine in reducing suffering and improving health rests mostly on shifting reliance away from idiosyncratic personal observations and opinion and toward formal scientific research evidence.
We cannot provide effective pet‐specific care without reliable information. We cannot assess health risks without understanding the causes of illness and the relationship between risk factors and health outcomes. We cannot provide effective preventive or therapeutic interventions without evidence showing which methods are effective and which are not. We cannot minimize the adverse effects of our treatments without understanding what the risks are and why they occur. EBVM makes effective care possible by generating the needed information and helping clinicians find and use it.
Evidence‐based veterinary medicine is also useful in meeting our ethical obligations to pet owners. These include not only providing the most effective care possible but also obtaining informed consent for our interventions. When we recommend a treatment to a pet owner using an evidence‐based approach, we can confidently identify the potential risks and benefits of the treatment and the degree of uncertainty about these based on reliable scientific information, rather than anecdote or opinion. We will not always be certain about the outcome, but we can give an informed estimate of the degree of uncertainty. This is an important element in gaining informed consent from clients.
Pet owners have an ethical and often a legal right to be informed about the possible risks and benefits of medical interventions. EBVM helps veterinarians fulfill our ethical obligations to clients by ensuring that the information we provide is as accurate and reliable as possible. Even when the evidence is limited and the level of uncertainty is high, as is often the case in veterinary medicine, EBVM helps the clinician to be transparent about this with pet owners and to provide the information needed for fully informed consent.
2.1.5 How Does EBVM Work in Practice?
Ideally, EBVM methods should be a core part of veterinary medical training. The habits of identifying specific information needs and then finding and critically evaluating scientific evidence are extremely useful once established, but some formal training and practice are required to develop these habits.
The basic steps in the process of integrating research evidence into clinical decision making are as follows.
1 Ask specific, answerable questions.
2 Locate relevant evidence.
3 Assess the reliability and applicability of this evidence.
4 Draw a conclusion.
5 Assign a level of confidence to this conclusion.
This is an iterative process that must be repeated as information needs change and new evidence becomes available.
Of course, in a busy clinical practice it is not possible to apply such a formal method to every question for every patient in real time. The goal of applied EBVM is to develop a personal knowledge base derived from explicit, critical assessment of scientific evidence which the veterinarian can then apply to individual patients as appropriate, guided by the unique circumstances of each case, the goals and resources of the owner, and the judgment of the clinician. The meaningful difference between this process and opinion‐based medicine is that the knowledge base a clinician uses to make recommendations is not a haphazard collection of information gleaned from sources of uncertain reliability but a set of conclusions with known provenance and a clearly established degree of uncertainty.
Figure 2.1.1 illustrates common types of evidence used to guide clinical decisions. Such evidence pyramids are helpful in establishing a degree of confidence in our conclusions. A recommendation based only on low‐quality
