Locating the Best Available Evidence for Clinical Care
This tutorial walks you through the first two steps of the evidence-based medicine process of 1) ASK
a pertinent and answerable clinical question and 2) ACQUIRE
the evidence by selecting and searching the best resource for your question. To be clear, the focus of this tutorial is finding the best evidence, with little information on the mechanics and strategies of using the resources.
STEP 1: Creating a Searchable Clinical Question Using PICO
In the Embark Program, we focused on developing a research question for your project and using PubMed and other resources to locate literature to support your topic. The reasons for searching the literature and resources appropriate for clinical questions are completely different from what you learned in conducting a research project.
Clinical questions are broken down into two types:1
- Background Questions simply look for background information on a disorder, test, treatment, etc. For example, what is appendicitis?
- Foreground Questions are related to a specific patient case or population and are broken down into four components:
- P = Patient or Population
- I = Intervention or Exposure
- C = Comparison, intervention, or exposure
- O = Outcome
You can use PICO to easily break down a patient case and develop a relevant clinical foreground question such as:
- How effective is a CT scan compared to ultrasound in diagnosing suspected appendicitis in adult patients?
STEP 2: Using the 6S Model to Locate the Best Available Evidence
Once you have a clear clinical question, it is time to find the best available evidence to answer that question. The 6S Model of pre-appraised, evidence-based medicine resources was developed by DiCenso, Bayley, and Haynes in 2009 to aid clinicians in organizing and remembering the various evidence-based medicine resources available.2 This pyramid is divided into 6 tiers starting with Studies at the bottom, Synopses of Studies, Syntheses, Synopses of Syntheses, Summaries and, finally, Systems. Each tier represents a particular type of study and the appropriate resource(s) to find that type of study.
As you move up the pyramid, the level and quality of evidence increases as does the relevance to clinical practice. Since you are most familiar with using PubMed, which falls at the bottom of the evidence pyramid, we'll start at the bottom and work our way up with Studies.
Use the Table of Contents to navigate to your desired page or click Next To Studies below to start looking at the bottom tier of the pyramid:
NEXT TO Studies >
Straus SE, Glasziou P, Richardson WS, Haynes RB. Asking answerable clinical questions. In: Evidence-based medicine: how to practice and teach it. 4th ed. Edinburgh, UK: Elsevier Churchill Livingstone; 2011:13 - 27.
DiCenso A, Bayley L, Haynes RB. Accessing pre-appraised evidence: fine-tuning the 5S model into a 6S model. Evid Based Nurs. 2009;12(4):99-101.
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