Evidence-based practice (EBP) is the process of systematically finding, appraising, and using contemporary research findings as a basis for clinical and policy decisions ( ). This involves the “bottom-up” five-step process of EBP first developed in McMaster University and the Centre for Evidence-Based Medicine (CEBM) ( ) ( Fig. 1 ). “Bottom-up” is a term coined by David Sackett and Paul Glasziou, directors of the CEBM, and denotes the practice of efficiently tracking down and appraising literature at a local level and applying it to local clinical practice ( ). The Internet has facilitated this practice such that any radiologist with a clinical question can efficiently explore the relevant literature, select data at the highest level of the hierarchy of evidence knowing it is the best current evidence, apply this knowledge to problems encountered in day-to-day practice, and evaluate its impact. Solutions that work for individual problems and circumstances can be derived and put into practice, with a clear awareness of their limitations ( ).
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Figure 1
The five-step process of evidence-based practice.
Step 1: Ask
The radiologist poses a focused clinical question regarding clinical data. The anatomy of the question involves four parts: the problem being addressed, the intervention being considered, the comparison of the intervention, and the outcome of interest. The EBP question format PICO can be used (Patient, Investigation, Comparison, and Outcomes of interest) ( ).
Step 2: Search
The next step is to find the evidence in the literature to answer the clinical question. There are many databases, search engines and guidelines that have facilitated EBP; of which MEDLINE and The Cochrane Collaboration may be especially useful. MEDLINE is the U.S. NLM bibliographic Website widely available to the public.
The Cochrane Collaboration is a quality filtered database that stratifies literature according to selected methodological criteria. The process of literary searching has been considered in detail in a recent Radiology article ( ). For our purposes, MEDLINE was used due to its large selection of radiological literature. The literature search was performed using MeSH terms, which applied to the clinical question.
Step 3: Appraise
The evidence retrieved is critically appraised in an explicit and structured manner to establish its validity, strength, and usefulness in practice. To effectively carry out the third step, literature is classified as belonging to one of several “domains.” Examples of domains are diagnosis, therapeutic benefit, therapeutic harm, reviews, clinical guidelines, prognosis, economic analysis, and qualitative research. The difference between evidence-based and “traditional” literature analysis is that the evidence-based researchers have described, in the peer-reviewed literature, an explicit process of appraisal for literature in each domain ( ). Factors that will act as sources of bias in study design have been identified, and mathematic analyses that will give the reader a clear idea of the strength, statistical significance, and possible clinical importance of the results are described. In addition to being located in the original literature ( ), these principles are now widely available in textbook form ( ) and on the Internet ( ). Their application to diagnostic radiology has been considered in detail in other publications ( ) and in a recent special series in Radiology ( ); interested readers are referred to these resources.
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Technology assessment
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Summary
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References
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