Can also use PICOT where T = type of question (eg: therapy) or T = Type of study (RCT or Cohort)
PICO clarifies the question, determines search concepts and type of study that is most appropriate to answer the question type.
A printable worksheet to help you ask focused clinical questions and structure search terms.
|Type of Question||Type of Study Design|
|Therapy||RCT > Cohort > Case control > Case series|
|Diagnosis||Prospective, blind comparison to a gold standard or Cross-sectional|
|Aetiology/Harm||Cohort > Case control > Case series|
|Prognosis||Cohort > Case control > Case series|
|Prevention||RCT > Cohort > Case control > Case series|
|Clinical exam||Prospective, blind comparison to a gold standard|
Study designs can be organised into a hierarchy. As you progress up the hierarchy from Case Reports/Case Series to Meta-analysis there are fewer studies but their methodology is stronger.
Evidence-Based Practice Information Resources Tutorial no.2
A short video looking at clinical questions and the types of studies used to answer these.
Cushing/Whitney Medical Library
Yale University School of Medicine