levels of evidence
the research pyramid
the gold standard of evidence is a systematic review: an article which examines, appraises and consolidates findings of all of the primary research for a medical question.
in the middle section, clinical research constitutes content that is vetted and verified such as clinically appraised topics and clinically appraised articles.
the bottom level of information in medical practice is opinion and background information. the kind of information that may be found in a textbook or encyclopedia.
sources on the chart to the left give tips on how to retrieve specific levels of evidence from journal databases.
dictionary of evidence based medicine terms center for evidence based medicine
searching for levels of evidence
|
systematic reviews |
health evidence.org. is a free index of systematic reviews from 1995 on in public health. registration required. search the database of abstracts of reviews (dare) subset in the ebm/cochrane database pubmed clinical queries search or conduct a search from the main screen and filter by article type cinahl (filter by publication type) |
|
clinically appraised topics |
ngc national guideline clearinghouse evidence based clinical practice guidelines. (us) updated weekly. |
|
clinically appraised individual articles |
the acp journal club can be accessed in print. it is also a subset of the ebm/cochrane database. evidence based nursing (print journal) |
|
searching multiple types of filtered ebm information |
the trip database in cinahl you may filter by multiple publication types such as case study, clinical trial, randomized control trial, research, systematic review) |
|
randomized controlled trials |
the cochrane central register of controlled trials is a subset of the ebm cochrane database pubmed – filter by article type after searching options for clinical trial, randomized control trial etc. cinahl – use the filter on the advanced search screen |
|
cohort studies |
there is no filer. in pubmed add the mesh subject cohort studies. in cinahl use the subject prospective studies |
|
case controlled studies/case series reports |
in cinahl refer to the subject heading case controlled studies |
|
background information |
for encyclopedias and reference sources see the reference sources section of this guide. northern ontario school of medicine may also be accessed. see instructions. |
comprehensive indexes to ebm
- acp journal club - see ebm reviews this link opens in a new windowcontains the fulltext of the cochrane database of systematic reviews (cdsr), best evidence (the american college of physicians journal club) and the database of abstracts of reviews of effectiveness (dare). also contains citations from the cochrane controlled trials register (no fulltext).
coverage: 1991-
best practices, guidelines, and other ebm sources
best practice guidelines
registered nurses of ontario best practice guidelines
nice clinical guidelines (national institute for health and clinical evidence, uk)
national guidelines clearinghouse (united states)
cma infobase - canadian medical association canadian clinical practice guidelines
public health agency of canada: best practices portal
evidence based search tools
synopses of single studies
evidence based nursing (journal)