No firm evidence was reached according to trial sequential analysis .
Conclusion There is insufficient data to recommend or refute the use of a specific material .
Adequacy and reporting of allocation concealment: review of recent trials published in four general medical journals
In r and omised controlled trials , allocation concealment ( separating the process of r and omisation from the recruitment of participants ) is important for rigorously design ed trials.1–4 In 1996 many major medical journals adopted the CONSORT statement ( whereby research ers have to include a short checklist of essential items and a flow diagram when reporting trials),5 and this move encouraged the reporting of allocation concealment . We review ed the prevalence of adequate allocation concealment and its association with the statistical significance of trial results . We search ed by h and four general medical journals ( the BMJ , JAMA , the Lancet , and the New Engl and Journal of Medicine ) to identify r and omised controlled trials published from January 2002 to December 2002 . We included articles if the authors reported that participants were r and omised and if the trial was published as a full report with the results of the main analyses . We categorised articles according to whether allocation concealment was adequate ( the person who executed the allocation sequence was different from the person who recruited
No firm evidence was reached according to trial sequential analysis .
Conclusion There is insufficient data to recommend or refute the use of a specific material .