Data from: Clinical study reports of randomised controlled trials: an exploratory review of previously confidential industry reports

Objective: To explore the structure and content of a non-random sample of clinical study reports (CSRs) to guide clinicians and systematic reviewers. Search strategy: We searched public sources and lodged Freedom of Information requests for previously confidential CSRs primarily written by industry for regulators. Selection criteria: CSR reporting sufficient information for extraction ("adequate"). Primary outcome measures: Presence and length of essential elements of trial design and reporting and compression factor (ratio of page length for CSR compared to its published counterpart in a scientific journal). Data extraction: data were extracted on standard forms and cross-checked for accuracy. Results: We assembled a population of 78 CSRs (covering 90 RCTs; 144,610 pages total) dated 1991-2011 of 14 pharmaceuticals. Report synopses had a median length of 5 pages, efficacy evaluation 13.5 pages, safety evaluation 17 pages, attached tables 337 pages, trial protocol 62 pages, statistical analysis plan 15 pages, and individual efficacy and safety listings had a median length of 447 and 109.5 pages, respectively. While 16 (21%) of CSRs contained completed case report forms, these were accessible to us in only one case (765 pages representing 16 individuals). Compression factors ranged between 1 and 8805. Conclusions: Clinical study reports represent a hitherto mostly hidden and untapped source of detailed and exhaustive data on each trial. They should be consulted by independent parties interested in a detailed record of a clinical trial, and should form the basic unit for evidence synthesis as their use is likely to minimize the problem of reporting bias. We cannot say whether our sample is representative and whether our conclusions are generalizable to an undefined and undefineable population of CSRs.研究目标：探索非随机抽样的临床研究报告（Clinical Study Reports, CSRs）的结构与内容，以期为临床医师与系统综述研究者提供指导。检索策略：我们检索了公开数据源，并提交信息自由申请，以获取此前主要由行业方为监管机构撰写的保密临床研究报告。纳入标准：纳入具备可提取充分信息的临床研究报告。主要结局指标：包括试验设计与报告的核心要素的存在情况、完整程度，以及压缩因子（即临床研究报告与其在科学期刊上发表的对应文章的页数比值）。数据提取：通过标准表格提取数据，并进行交叉核对以确保准确性。研究结果：我们共收集了1991年至2011年间的78份临床研究报告，涵盖90项随机对照试验（Randomized Controlled Trial, RCT），总页数达144610页，涉及14种药物。其中，报告概要的中位页数为5页，疗效评价部分为13.5页，安全性评价部分为17页，附属表格为337页，试验方案为62页，统计分析计划为15页，个体疗效与安全性汇总表的中位页数分别为447页与109.5页。16份（21%）临床研究报告包含完整的病例报告表（Case Report Form, CRF），但仅1份可供我们获取（765页，涉及16名受试者）。压缩因子的取值范围为1至8805。研究结论：临床研究报告是迄今为止大多未被发掘与利用的、包含每项试验详尽数据的资源。对临床试验详细记录感兴趣的独立研究者应当参考此类报告，且其应作为证据合成的基本单元，因为使用临床研究报告或可最大程度减少报告偏倚问题。我们无法确定本研究的抽样是否具有代表性，也无法确定我们的结论能否推广至未被明确界定且无法界定的临床研究报告群体。