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PICO is a framework for asking focused clinical questions.
PICO stands for:
Patient and Problem
Intervention or exposure
Comparison or Control
You may hear your professor say that you need to look in the grey literature for information. In its most simple definition, grey literature is anything outside of the usual academic (book and journal) publishing world. Grey literature can be government documents, agency reports, white papers, and other non-published items. For example Evidence Based Clinical Guidelines could often be considered grey literature.
Hierarchy of Evidence Summary
a. Evidence of a systematic review or meta analysis of all relevant randomized controlled trials (RCT), or evidence-based clinical practice guidelines based on the above.
b. Evidence of a systematic review of RCTs
c. Evidence of a systematic review of nonrandomized trials
a. Evidence from at least 1 RCT.
b. Single nonrandomized trial
Level III: Evidence from a systematic review of correlational/observational studies
Level IV: Evidence from a single correlational/observational study
Level V: Evidence from systematic reviews of descriptive, qualitative or physiologic studies.
Level VI: Evidence from a single descriptive, qualitative, or physiologic study.
Level VII: Evidence of authority opinion or reports of expert committees.
Pyramid modified from: Navigating the Maze, University of Virginia, Health Sciences Library, by University of Washington. Health Sciences Library and Information Center
Cochrane Database of Systematic Reviews:
Other Systematic Reviews and Meta-Analyses:
Journal Articles and Original Studies:
Clinical Research Critiques:
Case Reports, Case Series, Other Articles, Practice Guidelines:
Clinical pathways, textbook summaries, practice guidelines:
Basic Information and Tutorials about EBP:
Writing your topic a PIO, PICO, PICOT question: