Re: GRADE Evidence to Decision (EtD) frameworks: a systematic and transparent approach to making well informed healthcare choices. 2: Clinical practice guidelines
Many thanks to Prof Ansari for his interest in and comments on the GRADE Evidence to Decision framework articles.
Prof Ansari's point about the plain language summary is interesting; it is indeed hard to capture health information in words-only without running the risk of introducing ambiguity, or misunderstandings. There are, I think, at least three things that mean that the Evidence to Decision framework can help to reduce this risk.
Firstly, although the confidence interval given for the risk of dying having taken dabigatran rather than warfarin runs from 17 fewer to 1 more per 1000 patients, the 'true' value is not equally likely to be any value in that range–it is much more likely to be around the point estimate of 8 fewer deaths than it is to be at the extreme end of the confidence interval of 1 more death. The bulk of the confidence interval is in favour of dabigatran for this outcome and we need to note that.
Secondly, the plain language text is in the example structured in that the wording is related to the size of the treatment effect, the confidence interval and the GRADE assessment of the uncertainty in the evidence. The word 'probably' is used carefully and as part of a consistent approach to producing a short, words-only summary of the evidence. How people interpret 'probably' will vary but how we use it in the Evidence to Decision framework should not. Here the plain language text intends to convey the message that while there is a chance that dabigatran increases the risk of dying, this is much less likely than that it reduces that risk.
Finally, the Evidence to Decision framework presents information in several forms, some words-only, others numerical, with the option for a user to dig deeper if needed. While words or numbers alone may at times be ambiguous, we hope that by providing information in a number of formats, the chance of ambiguity is reduced and people can reach more informed conclusions.
Competing interests: I am a coauthor of the paper being discussed.