= P =


Permuted index

The Permuted index is an alphabetical list of all entry terms of a thesaurus. The entry term sends to the retained term (Subject Heading).


PICO is useful for medical questions and for topics where one thing is being compared with another.

Patient :.

This is the “Who”. For this you need to think of age, sex, ethnic origins or other defining characteristics of the patient and the population

Intervention :

This is also sometimes known as exposure, and makes up the “What”. This is what is happening to the patient or population, so it could be a drug or a therapy, a screening questionnaire or a health improvement programme.

Comparison :

With what is the intervention (or indeed population) being compared? This could be a control group.

Outcome :

What outcome do you expect to see? For example, you may be interested in knowing whether an intervention has a health benefit, or whether an exposure results in mortality.

Source : NHS FIFE LIBRARY SERVICES: Guide to Literature Searching. Available from: http://www.nhsfifelibraries.scot.nhs.uk/publications/litsearching.doc


PICO-Timeframe :

This refers to one or more time-related variables such as the length of time the treatment should be prescribed or the point at which the outcome is measured.


Type of study design




P Population
I Index test
R Reference test
T Target disorer


Precision is the proportion of retrieved articles that are of high quality

Source : http://hiru.mcmaster.ca/hiru/HIRU_Hedges_home.aspx