Investigation of discrepancies between direct and indirect comparison of competing healthcare interventions

要从一种疾病的几种可用的治疗方法中选择最好的治疗方法，最好的证据来自随机试验(RCT)，其中不同的治疗方法已经被直接相互测试(直接比较)。当现有的治疗方法还没有在随机对照试验中进行直接比较时，一种称为调整后间接比较的统计学方法可能会有帮助。然而，这种间接比较方法可能会产生与不同处理的直接比较不同的结果。我们的目标是调查与直接方法和间接方法之间的差异相关的因素。我们将看看间接比较是否给出了与直接比较不同处理的试验相同的答案。如果这两种方法给出的答案不同，我们将仔细研究这些研究，并试图找出可能导致差异的原因。我们计划进行的研究非常重要，因为在没有直接比较研究的情况下，国家临床卓越研究所等政府机构可能不得不使用间接比较方法来选择治疗方法。我们的研究结果应该有助于我们认识到间接比较可能是一个好的、可靠的选择的情况，以及它可能给我们错误的答案的情况。

To choose the best treatment from several available treatments to an illness, the best evidence is from randomised trials (RCTs) where different treatments have been directly tested against each other (direct comparison). A statistical method known as adjusted indirect comparison may be helpful when available treatments have not been directly compared in RCTs. However, this indirect comparison method may produce results that are different from a direct comparison of different treatments. We aim to investigate factors associated with the difference between direct and indirect approaches. We will see if indirect comparison gives the same answer as trials where the different treatments have been directly compared. If the two methods give different answers, we will look through the studies in detail, and try to work out what may have caused the difference. The research we plan to do is very important because government bodies like the National Institute of Clinical Excellence may have to use indirect comparison methods in choosing treatments, when no direct comparison study is available. Our research findings should help us recognize situations where the indirect comparison may be a good, reliable choice, and also when it can give us wrong answers.