Has open data arrived at the British Medical Journal (BMJ)? An observational study

Objective: To quantify data sharing policy compliance at the BMJ by analysing the rate of data sharing practices, and investigate attitudes and examine barriers towards data sharing. Design: Observational study. Setting: The BMJ research archive. Participants: 160 randomly sampled BMJ research articles, excluding meta-analysis and systematic reviews. Main outcome measures: Percentages of research articles that indicated the availability of their raw datasets in their data sharing statements and those that provided their datasets upon request. Results: Fifty out of 160 (31%) research articles indicated the availability of their datasets. Twelve used publicly available data and the remaining 38 were sent email requests to access their datasets. Only 1 publicly available dataset could be accessed and only 6 out of 38 shared their data via e-mail. So only 7/160 research articles shared their datasets, 4.4% (95% confidence interval: 1.8% to 8.8%). Conclusions: Despite the BMJ’s strong data sharing policy, sharing rates are low. Possible explanations for low data sharing rates could be: the wording of the BMJ data sharing policy, which leaves room for individual interpretation and possible loopholes; that our email requests ended up in researchers spam folders; and, that researchers are not rewarded in the scientific community for sharing their data. It might be time for a more effective data sharing policy and better incentives for health and medical researchers to share their data.

研究目标：通过分析数据共享实践发生率，量化英国医学期刊（BMJ）对其数据共享政策的遵守情况，并调查研究者对数据共享的态度，同时梳理数据共享面临的障碍。
研究设计：观察性研究。
研究场景：BMJ研究档案库。
研究对象：随机抽取的160篇BMJ刊发的研究论文，排除荟萃分析（meta-analysis）与系统综述（systematic reviews）类文章。
主要结局指标：在数据共享声明中提及原始数据集（raw datasets）可获取的研究论文占比，以及可应要求提供数据集的研究论文占比。
结果：160篇论文中，共有50篇（31%）提及数据集可获取。其中12篇采用公开可用数据集，剩余38篇需通过邮件申请获取数据集。仅1份公开可用数据集可直接访问，38份需邮件申请的数据集中仅有6份通过邮件完成共享。综上，160篇论文中仅7篇实现了数据集共享，占比4.4%（95%置信区间（confidence interval）：1.8%~8.8%）。
结论：尽管BMJ出台了严格的数据共享政策，但实际数据共享率仍较低。数据共享率偏低的可能原因包括：BMJ数据共享政策的表述存在个体解读空间与潜在漏洞；本次邮件申请最终进入了研究者的垃圾邮件文件夹；以及科学界未对研究者共享数据的行为给予激励。当前或需出台更有效的数据共享政策，并为健康与医学研究者提供更完善的数据共享激励机制。