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Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

—Samuel Johnson

*Mr. Ketterman's Case

Mr. Ketterman has several common health problems. I know there is a lot of information out there to help me understand his illnesses and plan his care. But I really don't know how to find it from credible sources. And I don't have hours available to do the searching. (See Appendix for Mr. Ketterman's health history.)

Finding answers to clinical questions can be a rewarding activity once you become familiar with the resources available to you and understand effective searching techniques. This chapter will focus on finding the evidence to clinical questions, where it is stored and how you can efficiently retrieve it. We will also suggest methods to manage the retrieved references and discuss how to keep current with new information.

As we discussed in Chapter 10, questions that occur during the care of patients usually fall into one of two broad categories: background questions and foreground questions. Background questions are concerned with general knowledge that helps us to understand the process of disease. According to Strauss,1 these questions have two parts: a root question such as "what" or "how" or "why" and an aspect of the disease or condition in question. These types of questions are usually answered with textbooks that provide general descriptions, overviews, and summary information. Foreground questions, often framed as PICO questions, are concerned with the management issues of individual patients with specific problems. Evidence based practice is centered on the care of specific patients and therefore provides a framework for addressing these foreground questions. Foreground questions are usually answered by current research, either in the form of filtered resources that select, analyze, and summarize studies as systematic reviews and preappraised topics or by primary studies that are reported in journals as original research, found through unfiltered research.


Filtered or preappraised resources have undergone a process of critical appraisal that systematically assesses the study for its methodology and validity, its results, and its relevance to making an informed clinical decision. Evidence-based practice requires the availability of current filtered evidence about diagnosis, treatment, and prevention of health disorders. Filtered evidence is characterized by a process of critical appraisal that evaluates the study for soundness of methodology, significance of results, and applicability to patients. The quality of the evidence is often visualized in the evidence pyramid, which shows the organization of resources based on the quality and comprehensiveness of the evidence (Fig. 11-1).

Figure 11-1

EBM Pyramid. (Reprinted with permission from EBM Pyramid and EBM Page Generator, copyright 2006 Trustees of Dartmouth College and Yale University. Produced by: Jan Glover, David Izzo, Karen Odato and Lei Wang.)

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