Skip to main content
It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.

General Surgery Residency

Evidence Based Practice Principles

For more details, visit the MAHEC Evidence Based Practice Guide


evidence based practice cycle


Hierarchy of evidence

Adapted from: DiCenso, A., Bayley, L., & Haynes, R. B. (2009). ACP Journal Club. Editorial: Accessing preappraised evidence: fine-tuning the 5S model into a 6S model. Annals of Internal Medicine, 151(6), JC3-2, JC3-3.

PICO, sometimes known as PICOTT, is a common approach for formulating clinical questions.







Patient / Population

Intervention / Indicator

Compare / Control



Type of Study or Question

Who are the relevant patients? Think about age, sex, geographic location, or specific characteristics that would be important to your question. What is the management strategy, diagnostic test, or exposure that you are interested in? Is there a control or alternative management strategy you would like to compare to the intervention or indicator? What are the patient-relevant consequences of the intervention? What time periods should be considered?   What study types are most likely to have the information you seek?  What clinical domain does your question fall under?


Also see our full EBP guide for additional details and alternative methods for formulating a question.

Don't Forget to Appraise the Evidence!

Appraising an article will general involve asking 3 broad question:
  • Are the results of the study valid (Internal validity)?
  • What are the results?
  • Are the results applicable to your patient (External validity)?


Assessment tools:

Search PubMed

Pubmed Logo

Need help searching? Email for assistance.