Data from: Do urology journals enforce trial registration? A cross-sectional study of published trials

OBJECTIVES: Trial registration can increase scientific transparency, but its implementation in specialty fields such as urology is unclear. We aimed to assess the endorsement of trial registration in the author instructions of urology-related journals and to assess whether randomized controlled trials (RCTs) in the field were effectively registered. DESIGN: Cross-sectional study of published trials. SETTING: We first assessed the author instructions of urology-related journals indexed in ‘Journal Citation Reports 2009’ (12/2010). Second, we divided the results into two groups of five journals each, all with high impact factors either requiring or not mentioning trial registration as a precondition for publication. We then performed a MEDLINE search to identify RCTs published in these 10 journals in 2009 (01/2011) and searched the clinical trials meta-search interface of the World Health Organization (ICTRP) for RCTs without information about registration (01–03/2011). Two authors independently assessed information regarding editorial advice about trial registration and identified the RCTs. RESULTS: Of 55 journals included, 26 (47.3%) contained some editorial advice about trial registration. Journals with high impact factors were more likely to mention trial registration directly (p=0.015). Of 106 RCTs published in 2009, 63 were registered (59.4%) with a tendency to an increase after 2005 (83.3%, p=0.035). 71.4% (30/42) of the RCTs that were published in journals mentioning and requiring registration, and 51.6% (33/64) of the RCTs that were published in journals that did not mention trial registration directly were registered. This difference was statistically significant (p=0.04). CONCLUSION: A statement of trial registration in author instructions resulted in a higher proportion of registered RCTs. Journals with high impact factors were more likely to mention trial registration. We suggest, though, that ensuring trial registration is not the responsibility only of the editors. Medical scientists should realize that trial registration is necessary to contribute to transparency in research.研究目的：临床试验注册可提升科研透明度，但泌尿外科学等专科领域的临床试验注册落实情况尚不明确。本研究旨在评估泌尿相关期刊作者指南中对临床试验注册的倡导情况，并考察该领域随机对照试验（randomized controlled trial, RCT）的实际注册完成情况。 研究设计：已发表试验的横断面研究。 研究实施细节：首先，我们对2010年12月收录于《2009年期刊引证报告（Journal Citation Reports 2009）》的泌尿相关期刊的作者指南进行评估。其次，将符合条件的期刊分为两组，每组各5种，均为高影响因子期刊，其中一组要求以临床试验注册作为论文发表的前提条件，另一组未提及该注册要求。随后，我们通过MEDLINE检索2009年（2011年1月）这10种期刊上发表的RCT，并通过世界卫生组织临床试验元检索接口（International Clinical Trials Registry Platform, ICTRP）检索未标注注册信息的RCT（2011年1-3月）。两名研究者独立评估期刊编辑关于临床试验注册的指导意见，并筛选纳入符合标准的RCT。 研究结果：本次纳入分析的55种期刊中，26种（47.3%）刊载了临床试验注册相关的编辑指导规范。高影响因子期刊更倾向于直接明确提及临床试验注册要求（p=0.015）。2009年发表的106项RCT中，63项完成了注册（59.4%），且2005年后RCT的注册率呈上升趋势（83.3%，p=0.035）。在提及并要求临床试验注册的期刊上发表的RCT中，71.4%（30/42）完成了注册；而在未直接提及临床试验注册要求的期刊上发表的RCT中，仅51.6%（33/64）完成了注册，二者差异具有统计学意义（p=0.04）。 研究结论：作者指南中明确临床试验注册相关要求，可有效提升RCT的注册比例。高影响因子期刊更倾向于提及临床试验注册要求。但本研究提示，保障临床试验注册并非仅为期刊编辑的责任。医学科研工作者应充分认识到，临床试验注册对于提升科研透明度具有不可或缺的必要性。