Structure of questions for evidence evaluation

This figure shows the structure of questions for evidence evaluation. Across the top, there are four boxes, each containing a letter from the acronym PICO (P.I.C.O.). Each of these boxes has a corresponding box beneath it to provide further explanation, as follows. “P” stands for “Population.” It describes a particular group of patients and may include a primary problem, disease, or coexisting conditions. An example of a population is cardiac arrest patients. “I” stands for “Intervention.” It includes the main intervention, prognostic factor, or exposure. An example of intervention is who received CPR. “C” stands for “Comparator.” It describes the main alternative; for example, compared with no CPR. “O” stands for “Outcome.” It is what is being accomplished, improved, or measured. Examples include neurologically intact survival, survival to discharge, and R.O.S.C. This figure is copyright 2015 by the American Heart Association. There is a caption beneath this Figure which reads: “Structure of questions for evidence evaluation.”