Risk of selection bias in randomized trials: further insight
نویسندگان
چکیده
منابع مشابه
Risk of selection bias in randomized trials: further insight
The quality of randomization is an under-appreciated facet of trial design. The present piece represents an advance in our collective understanding of how allocation concealment and randomization relate to risk of selection bias in randomized trials, and other measures are also considered. Though the overwhelming majority of the advice given is timely and correct, it is more instructive to focu...
متن کاملRisk of selection bias in randomised trials
BACKGROUND Selection bias occurs when recruiters selectively enrol patients into the trial based on what the next treatment allocation is likely to be. This can occur even if appropriate allocation concealment is used if recruiters can guess the next treatment assignment with some degree of accuracy. This typically occurs in unblinded trials when restricted randomisation is implemented to force...
متن کاملBlindness in Randomized Controlled Trials
In combination with randomization, blinding or masking is an important factor in randomized controlled trials (RCTs), particularly in trials that assess therapeutic effects. Here an attempt is made to explain blindness and why it is important. In clinical trials, blinding is defined as the condition imposed on a study in which study participants, health care providers and assessors collecting o...
متن کاملThe impact of selection bias in randomized multi-arm parallel group clinical trials
The impact of selection bias on the results of clinical trials has been analyzed extensively for trials of two treatments, yet its impact in multi-arm trials is still unknown. In this paper, we investigate selection bias in multi-arm trials by its impact on the type I error probability. We propose two models for selection bias, so-called biasing policies, that both extend the classic guessing s...
متن کاملPatient enrollment in medical trials: Selection bias in a randomized experiment
Self-selection can bias estimates of treatment effects from randomized experiments if one is interested not merely in the effect of treatment on the treated, but in extrapolating results to the general population. This paper employs the Roy model to study this problem in the context of medical trials. The main insight is that, as the probability of receiving active treatment rises, patients who...
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ژورنال
عنوان ژورنال: Trials
سال: 2016
ISSN: 1745-6215
DOI: 10.1186/s13063-016-1597-5