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

为了从几种可用的治疗方法中选择最佳治疗方法，最好的证据来自随机试验（RCT），其中不同的治疗方法直接相互测试（直接比较）。当现有的治疗方法在RCT中没有直接比较时，称为调整的间接比较的统计方法可能会有所帮助。然而，这种间接比较方法可能会产生与直接比较不同治疗方法不同的结果。我们的目的是调查与直接和间接方法之间的差异相关的因素。我们将看到间接比较是否与直接比较不同治疗的试验得出相同的答案。如果这两种方法给出的答案不同，我们将详细研究这些研究，并试图找出导致差异的原因。我们计划进行的研究非常重要，因为当没有直接比较研究时，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帮助我们认识到间接比较可能是一个好的，可靠的选择，也可以给我们错误的答案。

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.