Scutt Polly, Woodhouse Lisa J, Montgomery Alan A, Bath Philip M
Stroke, Division of Clinical Neuroscience, University of Nottingham, Nottingham, UK.
Hearing Sciences, NIHR Nottingham Biomedical Research Centre, Nottingham, UK.
BMJ Open. 2020 Sep 9;10(9):e038765. doi: 10.1136/bmjopen-2020-038765.
Meta-analysis based on individual patient data (IPD) from randomised trials is superior to using published summary data since it facilitates subgroup and multiple variable analyses. Guidelines and funders expect that researchers share IPD for bona fide analyses, but in practice, this is done variably. Here, we report the experience of obtaining IPD for two collaborative analysis studies.
Two linked studies required IPD from published randomised trials. The leading researchers for eligible trials were approached and asked to share IPD including trial characteristics, patient demographics, baseline clinical data and outcome measures.
Participants in eligible randomised controlled trials included patients with or at risk of cognitive decline/vascular events.
Numbers (%) of trials where the leading researcher responded favourably/negatively or did not respond. If negative, reasons behind the response were collected. If positive, methods used to share IPD were recorded.
Across the two studies, 391 completed trials were identified. Email addresses for researchers were found for 313 (80%) of the trials. One hundred and forty-eight (47%) researchers did not respond despite being sent multiple emails. Following contact, positive initial responses were received from 92 researchers, resulting in IPD being shared for 78 trials. Eighty-seven (28%) researchers declined to share data; justifications were recorded. The median time from first request to accessing data in one study was 241 (IQR 383.3) days. IPD sources included: direct from researcher, via academic trial funders repository and a website requiring remote analysis of commercial data. Where data were shared, a variety of methods were used to transfer data.
Sharing of IPD from trials is desirable and a requirement of many funding bodies. However, accessing IPD faces multiple challenges including refusals to share, delays in access to data and having to perform analyses on a remote website.
Not applicable.
基于随机试验个体患者数据（IPD）的荟萃分析优于使用已发表的汇总数据，因为它有助于亚组分析和多变量分析。指南制定者和资助者期望研究人员为了真实的分析共享IPD，但在实际操作中，情况各不相同。在此，我们报告两项合作分析研究获取IPD的经验。
两项相关研究需要已发表随机试验的IPD。我们联系了符合条件试验的主要研究者，请求他们共享IPD，包括试验特征、患者人口统计学数据、基线临床数据和结局指标。
符合条件的随机对照试验参与者包括有认知功能下降/血管事件风险或已发生认知功能下降/血管事件的患者。
主要研究者给予肯定/否定答复或未答复的试验数量（%）。如果是否定答复，收集答复背后的原因。如果是肯定答复，记录共享IPD所使用的方法。
在两项研究中，共识别出391项完成的试验。找到了313项（80%）试验的研究者电子邮件地址。尽管多次发送电子邮件，仍有148名（47%）研究者未回复。经过联系，92名研究者给予了肯定的初步答复，78项试验的IPD得以共享。87名（28%）研究者拒绝共享数据，并记录了理由。在一项研究中，从首次请求到获取数据的中位时间为241（四分位间距383.3）天。IPD来源包括：直接来自研究者、通过学术试验资助者资料库以及一个需要对商业数据进行远程分析的网站。在共享数据的情况下，使用了多种方法来传输数据。
试验IPD的共享是可取的，也是许多资助机构的要求。然而，获取IPD面临多重挑战，包括拒绝共享、获取数据延迟以及必须在远程网站上进行分析。
不适用。
