The EBP movement has given rise to considerable debate, with both advocates and critics. Supporters argue that EBP offers a solution to improving health care qual- ity in our current cost-constrained environment. They argue that a rational approach is needed to provide the best possible care to the most people, with the most cost-effective use of resources. Advocates also note that EBP provides an important framework for self-directed lifelong learning that is essential in an era of rapid clinical advances and the information explosion. Critics worry that the advan- tages of EBP are exaggerated and that individual clinical judgments and patient inputs are being devalued. They are also concerned that insufficient attention is being paid to the role of qualitative research. Although there is a need for close scrutiny of how the EBP journey unfolds, it seems likely that the EBP path is one that health care professions will follow in the years ahead.
Overview of the Evidence-Based Practice Movement
A keystone of the EBP movement is the Cochrane Collaboration, which was founded in the United Kingdom based on the work of British epidemiologist Archie Cochrane. Cochrane published an influential book in the early 1970s that drew attention to the dearth of solid evidence about the effects of health care. He called for efforts to make research summaries about interventions available to physicians and other health care providers. This eventually led to the development of the Cochrane Center in Oxford in 1993, and the international Cochrane Collaboration, with centers now established in over a dozen locations throughout the world. Its aim is to help providers make good decisions about health care by preparing, maintain- ing, and disseminating systematic reviews of the effects of health care interventions.
At about the same time that the Cochrane Collaboration got under way, a group from McMaster Medical School in Canada developed a clinical learning strategy they called evidence-based medicine. The evidence-based medicine movement, pio- neered by Dr. David Sackett, has broadened to the use of best evidence by allhealth care practitioners in a multidisciplinary team.
EBP has been considered a major paradigm shift for health care education and practice. In the EBP environment, a skillful clinician can no longer rely on a repos- itory of memorized information, but rather must be adept in accessing, evaluating, synthesizing, and using new research evidence.
Types of Evidence and Evidence Hierarchies
No consensus exists about what constitutes usable evidence for EBP, but there is general agreement that findings from rigorous research are paramount. There is, however, some debate about what constitutes “rigorous” research and what quali- fies as “best”evidence.
In the initial phases of the EBP movement, there was a definite bias toward reliance on information from a type of study called a randomized controlled trial(or, sometimes, a randomized clinical trial, RCT). This bias stemmed, in part, from the fact that the Cochrane Collaboration initially focused on evidence about the effec- tiveness of interventions, rather than about health care issues more generally. As we explain in Chapter 9, the strategies used in RCTs are especially well-suited for draw- ing conclusions about the effects of health care interventions. The bias in ranking sources of evidence primarily in terms of questions about effective treatments led to some resistance to EBP by nurses who felt that evidence from qualitative and non-RCT studies would be ignored.
Positions about the contribution of various types of evidence are less rigid than previously. Nevertheless, most published evidence hierarchies, which rank evidence sources according to the strength of the evidence they provide, look something like the one shown in Figure 2.1. This figure, adapted from schemes presented in several references on EBP (DiCenso et al., 2005; Melnyk & Fineout- Overholt, 2005) shows a seven-level hierarchy that has systematic reviews of RCTs at its pinnacle. Systematic reviews of nonrandomized clinical trials (Level Ib) offer less powerful evidence. The second rung of the hierarchy is individual RCT
a. Systematic review of RCTs
a. Single RCT
Systematic review of correlational/observational studies
Single correlational/observational study
Single descriptive/qualitative/physiologic study Systematic review of descriptive/qualitative/physiologic studies
Opinions of authorities, expert committees b. Systematic review of
nonrandomized trials
b. Single nonrandomized trial Level I
Level II
Level III
Level IV
Level V
Level VI
Level VII
Evidence hierarchy: Levels of evidence regarding effectiveness of an intervention.
FIGURE 2.1
studies, and so on (the terms in this figure are explained in subsequent chapters of this book). At the bottom of this evidence hierarchy is found opinions from experts.
Of course, within any level in an evidence hierarchy, evidence quality can vary considerably. For example, an individual RCT (Level IIa) could be well designed, yielding persuasive evidence, or it could be so flawed that the evidence would be useless. We must also emphasize that the hierarchy in Figure 2.1 is not universally appropriate—a point that is not always made sufficiently clear. This hierarchy has merit for ranking evidence for certain clinical questions, but not others. In partic- ular, this hierarchy is appropriate with regard to cause-probingquestions, especially questions about the effects of clinical interventions. For example, evidence about the efficacy of massage therapy on pain in cancer patients would be classified according to this hierarchy, but the hierarchy would not be relevant for ranking evi- dence relating to such questions as the following: What is the experience of pain like for patients with cancer? What percentage of cancer patients experience intense pain, and for how long does the pain persist?
Thus, in nursing, best evidence refers generally to findings from research that are methodologically appropriate, rigorous, and clinically relevant for answering pressing questions—questions not only about the efficacy, safety, and cost- effectiveness of nursing interventions, but also about the reliability of nursing assessment measures, the determinants of health and well-being, the meaning of health or illness, and the nature of patients’ experiences. Confidence in the evidence is enhanced when the research methods are compelling, when there have been mul- tiple confirmatory replication studies, and when the evidence has been systemati- cally evaluated and synthesized.
Barriers to Research Utilization and Evidence-Based Practice
Nurses have completed many studies about EBP and the translation of research into practice, including research on factors that hinder or facilitate EBP. This is an important area of research, because the findings indicate ways in which EBP efforts can be promoted or undermined, and thus suggest issues that need to be addressed in advancing evidence-based nursing. Studies that have explored barriers to research use have yielded remarkably similar results in numerous countries about constraints clinical nurses face. Most barriers fall into one of three categories:
(1) quality and nature of the research, (2) nurses’ characteristics, and (3) organiza- tional factors.
With regard to the research itself, the main problem is that for some practice areas, availability of high-quality research evidence is limited. There remains an ongoing need for research that directly addresses pressing clinical problems, for methodologically strong and generalizable studies, and for replication of studies in a range of settings. Another issue is that nurse researchers need to improve their ability to communicate their findings (and the clinical implications of their find- ings) to practicing nurses.
Nurses’ attitudes and education consistently have emerged as potential barriers to RU and EBP. Studies have found that some nurses do not value research or believe in the benefits of EBP, and others are simply resistant to change. Fortu- nately, there is growing evidence from international surveys that many nurses do
value research and want to be involved in research-related activities. Additional barriers, however, are that many nurses do not know how to access research infor- mation and do not possess the skills to critically evaluate research findings—and even those who do may not know how to effectively incorporate research evidence into clinical decision making.
Finally, many of the impediments to using research in practice are organiza- tional. “Unit culture” has been found to be a major factor in research use (Pepler, Edgar, Frisch, Rennick, Swidzinsky, White, et al., 2005), and administrative and other organizational barriers have repeatedly been found to play a role. Although many organizations support the idea of EBP in theory, they do not always provide the necessary supports in terms of staff release time and resources. EBP will become part of organizational norms only if there is a commitment on the part of managers and administrators. Strong leadership in health care organizations is essential to making EBP happen.