Term: Evidence Based Medicine (EBM)


The Center for Evidence-Based Medicine describes EBM as "the conscientious, explicit and judicious use of the current best evidence in making decisions about the care of individual patients."In other words, Evidence Based Medicine assists the Doctor in chosing what treatment will be done to the patient. EBM provides the doctor with the most up to date quality information in regards to the patient they are treating at that time.

EBM categorized evidence based on the conditions the trials were conducted under. The highest rating goes to the trials that were randomized, double blind, and placebo controlled. The lowest rating is given when only the opinions of respected authorities based on clinical experience, descriptive studies, or reports of expert committees are the evidence. There are generally an average 5 ratings total. Below is a visual example of evidence rating.

The Cochrane Database is considered the elite source of information to use in EBM. All of their studies are throughly reviewed and only the best of the best is inserted into their database.

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EBM also categorizes recommended clinical services by taking into consideration the risk, benefit, and the level of evidence as listed above. The highest level goes to the service whos benefits greatly outweigh potential risks, meaning the doctor should highly recommend it. The lowest ranking goes to services whos risk cannot be assessed due to poor quality, or inconsistant trials. The doctor in this case would explain to the patient how uncertain the results would be.

Mathmatical tools to determine effectiveness of a certain treatment.
  • Likelihood ratios - signifies how useful a test is
  • AUR-ROC curves - shows relationship between sensitivity and specificity
  • Number needed to treat/ Number needed to harm - tells the ratio of patients that respond to a certain test

**Limitations to EMB
  • Ethics, performing some studies of treatment can potentially cause more harm than good.
  • Costs
  • Bias
  • Demographics

  • Prioritize clinical tests
  • Predict outcomes of treatment
  • Signify how credible
  • Combines clinical expertise with current best evidence when making treatment decisions
  • Improve treatment Quality
  • Provide more consistant treatment
  • Allows more efficient use of time

Web Resources:
Centre for Evidence Based Medicine, British Medical Journal

Related Terminology:
Specificity, Sensitivity, Randomized, Double Blind, Placebo controlled, Liklihood ratio

Wikipedia, Public Health Information and Data Tutorial, CEBM