ReviewReliable assessment of the effects of treatment on mortality and major morbidity, I: clinical trials
Section snippets
Proper randomisation
The fundamental reason for random allocation of treatment in clinical trials is to maximise the likelihood that each type of patient will have been allocated in similar proportions to the different treatment strategies being investigated.10 In a properly randomised trial, the decision to enter a patient is made irreversibly in ignorance of which trial treatments that patient will be allocated. Foreknowledge of the next treatment allocation could affect the decision to enter the patient, and
SUMMARY: The need for large-scale randomised evidence
In a world in which moderate effects of treatment on mortality or major morbidity are generally more plausible than large effects, claims of striking effects from small-scale randomised trials, and from other sources (including observational studies1, will often prove evanescent. The assumption that both a moderate difference or no difference may be plausible, and that an extreme difference is much less so, has surprisingly strong consequences for the interpretation of evidence from trials. In
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