OBJECTIVES To evaluate the compliance with prospective registration and inclusion of the trial registration number (TRN) in published randomised controlled trials (RCTs), and to analyse the rationale behind, and detect selective registration bias in, retrospective trial registration. DESIGN Cross sectional analysis. DATA SOURCES PubMed, the 17 World Health Organization's trial registries, University of Toronto library, International Committee of Medical Journal Editors (ICMJE) list of member journals, and the InCites Journal Citation Reports. STUDY SELECTION CRITERIA RCTs registered in any WHO trial registry and published in any PubMed indexed journal in 2018. RESULTS This study included 10 500 manuscripts published in 2105 journals. Overall, 71.2% (7473/10500) reported the TRN and 41.7% (3013/7218) complied with prospective trial registration. The univariable and multivariable analyses reported significant relations (P<0.05) between reporting the TRN and the impact factor and ICMJE membership of the publishing journal. A significant relation (P<0.05) was also observed between prospective trial registration and the registry, region, condition, funding, trial size, interval between paper registration and submission dates, impact factor, and ICMJE membership of the publishing journal. A manuscript published in an ICMJE member journal was 5.8 times more likely to include the TRN (odds ratio 5.8, 95% confidence interval 4.0 to 8.2), and a published trial was 1.8 times more likely to be registered prospectively (1.8, 1.5 to 2.2) when published in an ICMJE member journal compared with other journals. This study detected a new form of bias, selective registration bias, with a higher proportion (85.2% (616/723)) of trials registered retrospectively within a year of submission for publication. Higher rates of retrospective registrations were observed within the first three to eight weeks after enrolment of study participants. Within the 286 RCTs registered retrospectively and published in an ICMJE member journal, only 2.8% (8/286) of the authors included a statement justifying the delayed registration. Reasons included lack of awareness, error of omission, and the registration process taking longer than anticipated. CONCLUSIONS This study found a high compliance in reporting of the TRN for trial papers published in ICMJE member journals, but prospective trial registration was low.

中文翻译：

---

随机临床试验中试验编号的前瞻性注册和报告：采用 ICMJE 和赫尔辛基宣言建议的全球横断面研究。

目的 评估前瞻性注册的合规性以及已发表的随机对照试验 (RCT) 中试验注册号 (TRN) 的纳入情况，分析背后的基本原理，并检测回顾性试验注册中的选择性注册偏倚。设计横截面分析。数据来源 PubMed、17 个世界卫生组织的试验注册中心、多伦多大学图书馆、国际医学期刊编辑委员会 (ICMJE) 成员期刊列表以及 InCites 期刊引文报告。研究选择标准 2018 年在任何 WHO 试验登记处注册并在任何 PubMed 索引期刊上发表的随机对照试验。 结果 本研究包括在 2105 种期刊上发表的 10 500 篇手稿。总体而言，71.2% (7473/10500) 报告了 TRN，41.7% (3013/7218) 遵守了前瞻性试验注册。单变量和多变量分析表明，报告 TRN 与出版期刊的影响因子和 ICMJE 会员资格之间存在显着关系 (P<0.05)。前瞻性试验注册与注册、地区、条件、资金、试验规模、论文注册和提交日期之间的间隔、影响因子和出版期刊的 ICMJE 会员资格之间也观察到显着关系（P<0.05）。在 ICMJE 会员期刊上发表的手稿包含 TRN 的可能性高出 5.8 倍（比值比 5.8，95% 置信区间 4.0 至 8.2），已发表的试验被前瞻性注册的可能性高出 1.8 倍（1.8、1.5 至 2.2） ）与其他期刊相比，在 ICMJE 成员期刊上发表时。这项研究发现了一种新形式的偏倚，即选择性注册偏倚，较高比例（85.2%（616/723））的试验在提交发表后一年内进行了回顾性注册。在研究参与者入组后的前三到八周内，观察到回顾性注册率较高。在回顾性注册并在 ICMJE 会员期刊上发表的 286 项 RCT 中，只有 2.8% (8/286) 的作者发表了证明延迟注册合理性的声明。原因包括缺乏认识、遗漏错误以及注册过程比预期时间长。结论 本研究发现 ICMJE 成员期刊上发表的试验论文 TRN 报告的合规性较高，但预期试验注册率较低。