I would like to expand on the comments made by Paul.
The paper by Treadwell reports the ECRI system for rating the stability
and strength of medical evidence. This system seems best suited for
summarizing the results of a large meta-analysis, while the GRADE system
is intended for summarizing a body of evidence for a technology, including
evidence on harms, benefits, and economics. The GRADE system provides
grades for both evidence and recommendations. Thus the ECRI system covers
only part of the area covered by the GRADE system.
Treadwell et al emphasize that gradings using their system are
transparent, i.e. users of evidence summaries could (if they wanted to)
see the reasoning underlying assignment of evidence grades. The authors
also stress the importance of distinguishing between what they call
quantitative conclusions (which answer the question "How well does it
work?") and qualitative conclusions (which answer the question "Does it
work?").
Systems for grading evidence (and recommendations) have two main aims: (i)
to aid thinking by people who review evidence and develop guidelines, and
(ii) to aid NOT thinking by people who use evidence reviews and
guidelines. Because not thinking can be embarrassing and dangerous it is
important that aids to not thinking are helpful and safe. I suspect that
Treadwell et al want encourage users of their reviews not to not notice
that the effects of an intervention are not clinically important (not
sorry about all the nots, they are not unimportant!!!).
Transparency is an important safety measure, as it means that people can,
and often will, check the basis for the conclusions. Errors will be
discovered more easily, and correct conclusions will carry more
credibility. However, I have not seen an ECRI review so cannot report how
well their aspirations for transparency are realized.
Michael Power
Clinical Knowledge Author, Guideline Developer and Informatician
Prodigy Knowledge www.prodigy.nhs.uk
Sowerby Centre for Health Informatics at Newcastle Ltd www.schin.co.uk
On Tue, 24 Oct 2006 18:36:34 +0100, Paul Glasziou
<[log in to unmask]> wrote:
>Dear Ulf
>Looks interesting but I can't see any immediate advantages over the
>GRADE tools:
>http://www.gradeworkinggroup.org/
>which are being developed by an international group who meet regularly
>to iron out problems,
>Paul Glasziou
>
>> Dear list.
>>
>> I was just shown:
>>
>> "A system for rating the stability and strength of medical evidence"
>> BMC Medical Research Methodology 2006, 6:52 doi:10.1186/1471-2288-6-52
>> by Jonathan R. Treadwell, Stephen J. Tregear, James T. Reston and
Charles
>>
>> M. Turkelson
>>
>
>
>--
>Paul Glasziou
>Director, Centre for Evidence-Based Medicine,
>Department of Primary Health Care,
>University of Oxford www.cebm.net
>ph +44-1865-227055 fax +44-1865-227036
>=========================================================================
|