Reading between the lines part 4: Cherry-picking the best results

Outcome reporting bias: cherry-picking the best results When planning an RCT, the choice of primary outcome is crucial. This is an integral part of the research question, and forms the basis of the sample size calculation. Secondary outcomes are also chosen, to give a wider indication of the effects of interventions, generate new hypotheses, and […]

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Reading between the lines part 2: Some ‘equal groups’ are more equal than others

Selection bias – some ‘equal groups’ are more equal than others The groups of participants receiving interventions should be equal, otherwise confounding variables might give one treatment an advantage over another. If there is a systematic reason for this, the study is at risk of selection bias.   Randomization (sequence generation) The first consideration is […]

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Clinical trials – reading between the lines.

Another new series of blogs here in the ADC website, from Ian Sinha of the Respiratory Unit, Alder Hey Children’s Hospital, Liverpool, UK, takes a look at explaining the deeper depths of critical appraisal of randomised controlled trials from the perspective of the Cochrane collaboration’s approach to this issue. – Archi   Clinical trials – reading between […]

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Debating devices

It’s really hard to persuade people that devices need evaluation like drugs do. This might be to do with the physical nature of a device: after all, if you can see the new cannula attachment, or special breathing mask, you know what it’s doing and what it must be making. Or it might be in […]

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