What do I do with the evidence?
Critical Appraisal
When you find article you will need to decide:
Is it a good article?
Can you use the results?
The Centre for Evidence Based Medicine has developed worksheets which take you through the most important questions for each type of research.
The Evidence Pyramid
As you move up the pyramid the amount of available literature decreases, but its relevance to the clinical setting increases.
Click on each of the sections below to see more description. |
| Expert opinion / Laboratory studies / Animal Research - Information usually starts with an idea or laboratory research. As these ideas turn into drugs and diagnostic tools they are tested in laboratories, in models, in vitro, in animals, and finally in humans. |
Case series/Case reports - http://library.downstate.edu/EBM2/2600.htm
These consist of collections of reports on the treatment of individual patients or a report on a single patient. They have no statistical validity as they do not use control groups to compare outcomes. |
Case control studies - http://library.downstate.edu/EBM2/2500.htm
Case control studies are studies in which patients who already have a specific condition are compared with people who do not. These are often less reliable than RCT and cohort studies because showing a statistical relationship doesn’t necessarily mean that one factor caused the other.
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Cohort Studies - http://library.downstate.edu/EBM2/2400.htm
A Cohort Study is a study in which patients who presently have a certain condition and/or receive a particular treatment are followed over time and compared with another group who are not affected by the condition or treatment being studied. |
Randomised control clinical trials (RCT) - http://library.downstate.edu/EBM2/2200.htm
These are carefully planned projects that study the effect of a therapy on real patients. They use methodologies such as randomization and blinding (that reduce the potential for bias) and that allow for comparison between intervention and control groups.
Double Blind studies - http://library.downstate.edu/EBM2/2300.htm
A double blind study is one in which neither the patient nor the physician knows whether the patient is receiving the treatment of interest or the control treatment. |
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Applying the Evidence
Once you have found the best evidence for your situation you need to work out how the results apply to your individual patient.
Questions to consider are:
- Is the treatment feasible in my setting?
- Is my patient too different from those in the study to be applicable?
- What are the other alternatives?
- Will the benefits outweigh any potential harm for my patient?
- What are my patients opinions?
You will learn more about critical appraisal, applying evidence-based medicine principles and understanding research methods and statistical tests as part of the Quality of Medical Practice element in the undergraduate medicine program. |
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