Abstract
n his recent BMJ Endgames “Explanatory trials versus pragmatic trials” Sedgwick stated that the example pragmatic trial for leg ulcers undertaken in the community “…would NOT be expected to have high internal validity” [1].
I disagree. Although others have made similar statements [2, 3] I am not aware of an evidence base supporting (or refuting) the belief that trials that take a more pragmatic approach sacrifice internal validity. The CONSORT extension for pragmatic trials [4] makes the same demands regarding reporting of information relevant for assessing internal validity as the full CONSORT Statement [5]; it does not suggest that these can be compromised in a trial taking a pragmatic approach. The only item that is different is blinding - “if blinding was not done, or was not possible, explain why” so even here the expectation is that to ensure internal validity, blinding should be carried out wherever possible.
I disagree. Although others have made similar statements [2, 3] I am not aware of an evidence base supporting (or refuting) the belief that trials that take a more pragmatic approach sacrifice internal validity. The CONSORT extension for pragmatic trials [4] makes the same demands regarding reporting of information relevant for assessing internal validity as the full CONSORT Statement [5]; it does not suggest that these can be compromised in a trial taking a pragmatic approach. The only item that is different is blinding - “if blinding was not done, or was not possible, explain why” so even here the expectation is that to ensure internal validity, blinding should be carried out wherever possible.
Original language | English |
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Pages (from-to) | 1 |
Number of pages | 1 |
Journal | BMJ |
Volume | 349 |
DOIs | |
Publication status | Published - 18 Nov 2014 |