Estimation and adjustment of bias in randomized evidence by using mixed treatment comparison meta-analysis
Estimation and adjustment of bias in randomized evidence by using mixed treatment comparison meta-analysis
复制标题
DOI：
10.1111/j.1467-985x.2010.00639.x
复制
发表时间：
2010-01-01
影响因子：
2
通讯作者：
Ades, A. E.
中科院分区：
文献类型：
--
作者：
Dias, S.;Welton, N. J.;Ades, A. E.
有很好的经验证据表明，随机对照试验的具体缺陷与治疗效果估计的夸大有关。混合治疗比较荟萃分析结合了来自几种治疗的试验数据，形成了一个比较网络，有可能在综合中估计偏倚参数，并产生偏倚调整后的治疗效果估计。我们提出了一个分层模型，在积极治疗与对照组的治疗比较中，偏差具有共同均值。从报道的信息来看，通常不清楚一项研究是否存在偏倚风险。我们扩展了我们的模型来估计特定研究有偏差的概率，其中“不清楚”研究的概率来自一个共同的beta分布。我们通过对预防儿童龋齿的四种氟化物治疗和两种对照干预措施的130项试验综合说明了这些方法。是否有足够的分配、隐藏和/或盲法被认为是研究是否存在偏倚风险的指标。偏倚校正降低了治疗的估计相对疗效和试验间异质性的程度。
There is good empirical evidence that specific flaws in the conduct of randomized controlled trials are associated with exaggeration of treatment effect estimates. Mixed treatment comparison meta-analysis, which combines data from trials on several treatments that form a network of comparisons, has the potential both to estimate bias parameters within the synthesis and to produce bias-adjusted estimates of treatment effects. We present a hierarchical model for bias with common mean across treatment comparisons of active treatment versus control. It is often unclear, from the information that is reported, whether a study is at risk of bias or not. We extend our model to estimate the probability that a particular study is biased, where the probabilities for the 'unclear' studies are drawn from a common beta distribution. We illustrate these methods with a synthesis of 130 trials on four fluoride treatments and two control interventions for the prevention of dental caries in children. Whether there is adequate allocation concealment and/or blinding are considered as indicators of whether a study is at risk of bias. Bias adjustment reduces the estimated relative efficacy of the treatments and the extent of between-trial heterogeneity.