Evidence Based Practice

This guide is designed to provide information on what Evidence Based Practice is and how to find evidence.

The PICO question framework

The first stage of any evidence-based practice process is formulating an answerable question. This forms the foundation for quality searching. A well-formulated question will facilitate the search for evidence and will assist you in determining whether the evidence is relevant to your question.

An answerable question has a format that follows the PICO concept. The acronym translates to:

  • P = populations/people/patient/problem
  • I = intervention(s) (or treatment)
  • C = comparison
  • O = outcome

Other variations of the PICO framework include:

  • PICOT (T = Types of studies, or Timeframes - used for time related variables such as prescribed treatment)
  • PICOS (S = Setting, Situation or Stakeholders)

An example of using PICO to formulate the question and search strategy

Example of the scenario that the question comes from:

A nurse in aged care home has a lot of patients who get bed sores because they are in bed all, or most of the day. Is there any way to stop them getting bedsores as often? And how can they be treated so that they don't keep getting worse?


The example question laid out using the PICO framework:

Population aged care residents
Outcome reduction in incidence and severity of bedsores

NOTE: You don't have to fill in all of the fields. In this case you can't fill in the intervention, because that is what you are trying to discover. And because there is no intervention, you can't add a comparison intervention either.


Example question reworded as a clinical question for research:

Which interventions reduce the incidence and severity of bed sores in residents of aged care facilities?


Keywords from the example question and possible alternatives:

Words from PICO Synonyms / Alternatives you could also use
aged care residents aged care, nursing home, aged, elderly, geriatric
bed sores bedsores, pressure sores, pressure ulcers, decubitus ulcers
reduction reduce, reducing, lessen, decrease, minimise, minimize, prevent, improve


The database search string from the example question

("aged care residents" OR "aged care" OR "nursing home" OR aged OR elderly OR geriatric) AND ("bed sores" OR bedsores OR "pressure sores" OR "pressure ulcers" OR "decubitus ulcers") AND (reduc* OR lessen OR decrease OR minimi?e OR prevent OR improve)


  • reduc* will tell the database to search for reduce, reduces, reduced, reducing, reduction, and reductions.
  • minimi?e will tell it to search for both minimise (English spelling) and minimize (American spelling).
  • Go to the Searching databases page for information on how to structure your search like this one.


Other limits you can apply in a database for this search

  • Age range, e.g. Aged 80 and over.
  • Subject headings, e.g. wound care. (You can use the database subject headings to narrow the focus of your search.)
  • Publication date range, e.g. in the last 10 years.
  • Publication type, e.g. case study. (Sometimes this is a filter. Sometimes you need to use it as a search term.)
  • Geography, e.g. Australia. (Sometimes this is a filter. Sometimes you need to use it as a search term.)

Printable PICO worksheet

This worksheet was adapted from Syrene A. Miller, PICO Worksheet and Search Strategy, National Center for Dental Hygiene Research.