Principles of evidence based medicine

EBM aims to promote new and innovative practices that are proven to work, and to disregard harmful and ineffective practices. The consequinces of EBM are effective, accurate and precise clinical interventions and diagnostic tests. Important EBM skills include the ability to find, critically appraise and incorporate sound scientific evidence. 

To incorporate EBM into clinical practice, 5 essential steps must be applied:

1. Formulate an answerable clinical question
2. Find evidence
3. Appraise the evidence
4. Apply the evidence
5. Evaluate performance

The main idea is to convert all the questions that arise from a difficult case into one structured clinical question.

A good clinical question should have 4 main points:

• patient or problem in question
• intervention, test or exposure of interest
• comparison interventions
• outcome of interest

These 4 points are also known as the abbreviation PICO. 

Various sources could help you find evidence. Be wary of textbooks or journals, as they may be out of date. Your colleagues may assist you, but the quality of information obtained from them may vary. The best places to go to find evidence are online electronic bibliographic databases. These databases contain a vast variety of articles, and thus require advances searching skills to be navigated effectively. These basic principles can be summarized in 4 essential steps. 

The following principles can be used to improve the quality of your searches when navigating an electronic bibliographic database:

1. Convert the problem into and answerable question using the PICO format. 
2. Decide on appropriate key words to make the search more accurate. 
3. Choose a bibliographic database within which to conduct your search, such as the Cochrane Library. 
4. Conduct the search

Decide on how useful or valid the articles that you have obtained are. The quality of research articles vary, and it is essential that you avoid using the evidence contained in unreliable articles. Oxford, UK developed tools for appraising research known as the Critical Appraisal Skills Programme, or CASP. These tools are freely available on the internet. 

Once we have critically appraised the evidence and decided on it's relevance, we can apply it in our practice. We now have to decide if this evidence is applicable to our patient or population. All aspects of the evidence should be fully discussed with the patient for them to make an informed decision. All costs and the availability of the treatment should be considered before applying the evidence. 

After completing all the previous steps, we should stand back and evaluate our actions throughout this process. We must look especially at our patient outcomes, and decide if patient care and outcome have improved. If not, we should learn from the experience for future reference.