The idea of a Hierarchy of Evidence is that there is a ranking of studies of different kinds in terms of how persuasive they are. It is not enough to simply say that “A study shows…” without also looking at what kind of study it is how powerful the results are. We look at the different kinds of studies and rank them from top to bottom.

Links

https://en.wikipedia.org/wiki/Hierarchy_of_evidence

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2707010/

http://www.phru.nhs.uk/casp/rcts.htm

https://en.wikipedia.org/wiki/Cohort_study

https://en.wikipedia.org/wiki/Framingham_Heart_Study

https://en.wikipedia.org/wiki/Case-control_studies

https://en.wikipedia.org/wiki/Cross-sectional_study

https://en.wikipedia.org/wiki/Case_reports

https://www.palain.com/?page_id=402