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SIGN Methodology
SIGN TO CONSIDER GRADEing
Since 1999 SIGN has used the system it developed from the original US Agency for Healthcare Policy and Research (as it then was) approach to grading recommendations in its guidelines. The levels of evidence based on study design, along with the ABCD grading of recommendations has become familiar to guideline developers and users in Scotland, the United Kingdom more generally, and in many other countries across the world.
In more recent years, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group has been developing a new approach to grading evidence that moves away from initial reliance on study design to consider the overall quality of evidence across outcomes. This approach is gaining wide acceptance by guideline developers across the world.
SIGN has been involved in the work of the GRADE group almost since its beginning, and has continued to evaluate its costs and benefits. It has become apparent that GRADE does offer some significant advantages over the existing system. The focus on patient important outcomes inherent in the GRADE process fits in particularly well with the patient-focused approach of SIGN, NHS Quality Improvement Scotland, and the wider NHS in Scotland. At its June 2009 meeting SIGN Council therefore took the decision that we should look at how we can best adopt or adapt GRADE to fit in with SIGNs’ established methodology. A Methodology Development Group is now looking at this in detail.
The extent of the task should not be underestimated, as it involves a substantial culture change for SIGN as well as a major task in explaining and justifying the changes to users of our guidelines.
To that end, progress will be regularly reported on this web site and SIGN staff will use any suitable opportunity to explain developments to interested parties. Any comments on these proposals are welcome, and should be addressed to robin.harbour@nhs.net
SIGN guidelines are based on a systematic review of the evidence, undertaken by guideline development group members, with support from the SIGN Executive.
SIGN Guideline Development Handbook: SIGN 50
A detailed description of SIGN’s methodology, together with examples of checklists, evidence tables and considered judgement forms, is given in our 50th guideline, generally referred to as SIGN 50.
SIGN 50 is updated regularly to take into account any changes in methodology.
Methodological Principles
SIGN guidelines are developed using an explicit methodology based on three core principles:
These principles have remained constant since SIGN was first established.
Useful tools for critical appraisal
Grading or GRADEing?
A symposium and debate on the grading of evidence in guidelines Presentations (MAY 2009)
All in Acrobat pdf format (info)
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