Preventing Bias in Cluster Randomised Trials
نویسندگان
چکیده
منابع مشابه
Preventing Bias in Cluster Randomised Trials
In randomised trials, internal validity is defined as ‘‘the extent to which the design and conduct of a study are likely to have prevented bias’’ [1,2]. In conducting such trials, trialists try to prevent selection bias through randomisation and allocation concealment (defined as ‘‘the process used to ensure that the person deciding to enter a participant into a randomised controlled trial does...
متن کاملMethodological bias in cluster randomised trials
BACKGROUND Cluster randomised trials can be susceptible to a range of methodological problems. These problems are not commonly recognised by many researchers. In this paper we discuss the issues that can lead to bias in cluster trials. METHODS We used a sample of cluster randomised trials from a recent review and from a systematic review of hip protectors. We compared the mean age of particip...
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Although randomised controlled trials are the reference methodology to assess the effects of therapeutic interventions, for interventions that naturally occur in groups of individuals random allocation of participants may be inappropriate. In these cases, the unit of random allocation may be the group or cluster, rather than the individual. Clinical trials that randomly allocate groups or clust...
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1 1Université François-Rabelais, Tours, France 2CHRU de Tours, INSERM CIC1415, Tours, France 3Centre de recherche Epidémiologie et Biostatistique, INSERM U1153, Paris, France 4Centre for Primary Care and Public Health, Queen Mary University of London, London, UK 5Department of Medical Statistics, London School of Hygiene and Tropical Medicine, London, UK Correspondence to: A Caille agnes.caille...
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ژورنال
عنوان ژورنال: PLoS Medicine
سال: 2009
ISSN: 1549-1676
DOI: 10.1371/journal.pmed.1000065