CONSORT 2010 Explanation and Elaboration: updated guidelines for reporting parallel group randomised trials

• Published in: BMJ 2010-03, Vol.340 (mar23 1), p.c869-c869
• Main Authors: Moher, David, Hopewell, Sally, Schulz, Kenneth F, Montori, Victor, Gøtzsche, Peter C, Devereaux, P J, Elbourne, Diana, Egger, Matthias, Altman, Douglas G
• Format: Article
• Language: English
• Subjects: Bias; Clinical trials; Clinical Trials (Epidemiology); Consensus; Content analysis; Decision making; Design; Editorials; Health care; Internet; Methods; Patients; Practice Guidelines as Topic - standards; Public health; Randomized Controlled Trials as Topic - standards; Report writing; Research Design - standards; Research Methods & Reporting
• ISSN: 0959-8138; 1468-5833; 1756-1833
• DOI: 10.1136/bmj.c869

[...]random assignment permits the use of probability theory to express the likelihood that any difference in outcome between intervention groups merely reflects chance. 26 Third, random allocation, in some situations, facilitates blinding the identity of treatments to the investigators, participants, and evaluators, possibly by use of a placebo, which reduces bias after assignment of treatments. 27 Of these three advantages, reducing selection bias at trial entry is usually the most important. 28 Successful randomisation in practice depends on two interrelated aspects-adequate generation of an unpredictable allocation sequence and concealment of that sequence until assignment occurs. 2 23 A key issue is whether the schedule is known or predictable by the people involved in allocating participants to the comparison groups. 29 The treatment allocation system should thus be set up so that the person enrolling participants does not know in advance which treatment the next person will get, a process termed allocation concealment. 2 23 Proper allocation concealment shields knowledge of forthcoming assignments, whereas proper random sequences prevent correct anticipation of future assignments based on knowledge of past assignments. [...]assessments will likely improve the clarity and transparency of published trials. Because CONSORT is an evolving document, it requires a dynamic process of continual assessment, refinement, and, if necessary, change, which is why we have this update of the checklist and explanatory article.