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 .
Blinding in randomised trials: hiding who got what
Blinding embodies a rich history spanning over two centuries . Most research ers worldwide underst and blinding terminology , but confusion lurks beyond a general comprehension . Terms such as single blind , double blind , and triple blind mean different things to different people . Moreover , many medical research ers confuse blinding with allocation concealment . Such confusion indicates misunderst and ings of both . The term blinding refers to keeping trial participants , investigators ( usually health-care providers ) , or assessors ( those collecting outcome data ) unaware of the assigned intervention , so that they will not be influenced by that knowledge . Blinding usually reduces differential assessment of outcomes ( information bias ) , but can also improve compliance and retention of trial participants while reducing biased supplemental care or treatment ( sometimes called co-intervention ) . Many investigators and readers naïvely consider a r and omised trial as high quality simply because it is double blind , as if double-blinding is the sine qua non of a r and omised controlled trial . Although double blinding ( blinding investigators , participants , and outcome assessors ) indicates a strong design , trials that are not double blinded should not automatically be deemed inferior . Rather than solely relying on terminology like double blinding , research ers should explicitly state who was blinded , and how . We recommend placing greater credence in results when investigators at least blind outcome assessment s , except with objective outcomes , such as death , which leave little room for bias . If investigators properly report their blinding efforts , readers can judge them . Unfortunately , many articles do not contain proper reporting . If an article cl aims blinding without any accompanying clarification , readers should remain sceptical about its effect on bias reduction
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 .