EDITED with answer (see below)... and another one
I'm curious to know where the 'levels of evidence' come from - I see them everywhere and have just found seemingly identical versions from doing a google search of
"systematic review or meta-analysis of randomised controlled trials"
Level of Evidence
1a Systematic review or meta-analysis of randomised controlled trials
1b At least one randomised controlled trial
2a At least one well-designed controlled study without randomisation
2b At least one well-designed quasi-experimental study, such as a cohort study
3 Well-designed non-experimental descriptive studies, such as comparative studies, correlation studies, case–control studies, and case series
4 Expert committee reports, or opinions and/or clinical experience of respected authorities
Since the results suggest that many people are using this exact format of words it suggests that they've got them either from each other or from one place. I feel I ought to know where. Do you?
Maybe I should try re-running that search with the American spelling...
EDIT: 16 August 2010
@jdc325 pointed out that this is probably the source
http://www.cks.nhs.uk/gi_upper_cancer_suspected/evidence/supporting_evidence/evidence_grading#
Eccles, M. and Mason, J. (2001) How to develop cost-conscious guidelines. Health Technology Assessment 5(16), 1-78.
Context page: http://www.hta.nhs.uk/project/995.asp
Jump to full text PDF: http://www.hta.nhs.uk/fullmono/mon516.pdf
EDIT: 21 August 2010
@vmontori pointed out that "Levels of Evidence outdated and incorrect, eg reviews are as reliable as individual study quality; opinions are not evidence but judgments about evidence" and subsequently recommended instead that I "lookup the GRADE system for quality of evidence - www.gradeworkinggroup.org"
Monday, 16 August 2010
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment
Comment policy: I enthusiastically welcome corrections and I entertain polite disagreement ;) Because of the nature of this blog it attracts a LOT - 5 a day at the moment - of spam comments (I write about spam practices,misleading marketing and unevidenced quackery) and so I'm more likely to post a pasted version of your comment, removing any hyperlinks.
Comments written in ALL CAPS LOCK will be deleted and I won't publish any pro-homeopathy comments, that ship has sailed I'm afraid (it's nonsense).