Trial registration as a safeguard against outcome reporting bias and spin? A case study of randomized controlled trials of acupuncture
Trial registration as a safeguard against outcome reporting bias and spin? A case study of randomized controlled trials of acupuncture
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DOI：
10.1371/journal.pone.0223305
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发表时间：
2019-10-03
期刊：
影响因子：
3.7
通讯作者：
Lee, Hyangsook
中科院分区：
文献类型：
--
作者：
Won, Jiyoon;Kim, Seoyeon;Lee, Hyangsook
背景和目标试验注册受到广泛认可，因为它不仅被认为可以提高报告的透明度和质量，而且有助于防止结果报告偏见和可能的扭曲，即所谓的特定报告，可能会扭曲结果的解释，从而误导读者。我们计划调查最近发表的针灸随机对照试验（RCT）的当前注册状况、前瞻性注册试验中的结果报告偏倚，以及试验注册与针灸RCT中存在旋转和方法学因素之间的关联。方法在PubMed、Cochrane对照试验中央注册库和Cochrane Central Register of Controlled Trials中检索近5年（2013年1月至2017年12月）英文发表的针灸RCT。 EMBASE。出版物和试验注册中确定的试验注册记录分为前瞻性注册、追溯注册或未注册。确定主要结果，并将结果的方向判断为统计显着（正）或统计不显着（负）。我们比较了注册和发布的主要结果，以评估结果报告偏差，并评估差异是否有利于具有统计显着性的结果。然后确定已发表的报告中主要结果在统计上不显着的旋转频率和策略。我们还分析了试验注册状态是否与方法学因素的旋转和质量相关。结果在 322 项纳入的随机对照试验中，41.9% (n = 135) 是前瞻性注册的。在 64 项前瞻性注册并指定主要结局的研究中，25 项试验在注册和公布的主要结局之间存在差异，其中 60%（15 项试验）支持统计显着的结果。在 169 项指定主要结局的研究中，试验注册状态与结果方向（即是否具有统计显着性）无关。在 78 项研究中，有 56.4% 的主要结果在统计上不显着，而声称有效果但不考虑在统计上不显着的主要结果是最常见的旋转策略。有和没有旋转的研究之间的试验注册状态没有统计学差异。结论虽然试验注册似乎随着时间的推移有所改善，但注册记录和出版物中的主要结果往往不一致，倾向于支持具有统计显着性的结果，而旋转在具有统计上不显着的主要结果的研究中很常见。该领域的期刊编辑和研究人员应警惕仍然普遍存在的报道偏见和歪曲事实。
Background and objectiveTrial registration is widely endorsed as it is considered not only to enhance transparency and quality of reporting but also to help safeguard against outcome reporting bias and probably spin, known as specific reporting that could distort the interpretation of results thus mislead readers. We planned to investigate the current registration status of recently published randomized controlled trials (RCTs) of acupuncture, outcome reporting bias in the prospectively registered trials, and the association between trial registration and presence of spin and methodological factors in acupuncture RCTs.MethodsAcupuncture RCTs published in English in recent 5 years (January 2013 to December 2017) were searched in PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Trial registration records identified in the publications and trial registries were classified into prospectively registered, retrospectively registered, or unregistered. Primary outcomes were identified and the direction of the results was judged as statistically significant (positive) or statistically nonsignificant (negative). We compared registered and published primary outcomes to assess outcome reporting bias and assessed whether discrepancies favored statistically significant outcomes. Frequency and strategies of spin in published reports with statistically nonsignificant results for primary outcomes were then identified. We also analyzed whether the trial registration status was associated with spin and quality of methodological factors.ResultsOf the 322 included RCTs, 41.9% (n = 135) were prospectively registered. Among 64 studies that were prospectively registered and specified primary outcomes, 25 trials had the discrepancies between the registered and published primary outcomes and 60% of them (15 trials) favored the statistically significant findings. Among 169 studies that specified primary outcomes, trial registration status was not associated with the direction of results, i.e., statistically significant or not. Spin was identified in 56.4% out of 78 studies with statistically nonsignificant primary outcomes and claiming efficacy with no consideration of statistically nonsignificant primary outcomes was the most common strategy for spin. Trial registration status was not statistically different between studies with and without spin.ConclusionWhile trial registration seemed to have improved over time, primary outcomes in registered records and publications were often inconsistent, tending to favor statistically significant findings and spin was common in studies with statistically nonsignificant primary outcomes. Journal editors and researchers in this field should be alerted to still prevalent reporting bias and spin.