Randomized clinical trials (RCTs) are rightfully valued as the primary source of research data that drives changes in practice and directs evidence-based care. However, the time and associated costs of initiating a trial and completing patient accrual and follow-up are important limitations. Among 28 phase 3 studies funded by the National Institute of Neurologic Disorders and Stroke of the National Institutes of Health, the total costs were more than $335 million, with a mean of approximately $12 million and a range from approximately $1 million to $64 million.¹ By comparison, data from administrative claims, clinical registries, and electronic health records are readily available, cost-effective, and efficient for conducting observational research. These favorable features make observational data powerful tools that, when used properly, could potentially increase the rate at which scientific evidence is incorporated into contemporaneous clinical practice.

合理地将随机临床试验（RCT）作为研究数据的主要来源，以推动实践的改变并指导循证护理。但是，开始试验以及完成患者应征和随访的时间和相关费用是重要的限制。在由美国国立卫生研究院神经病学和中风研究所资助的28项三期研究中，总费用超过3.35亿美元，平均约1200万美元，范围从约100万美元到6400万美元不等。^1个相比之下，来自行政要求，临床登记和电子健康记录的数据随时可用，具有成本效益并且可以有效地进行观察研究。这些有利的功能使观察数据成为强大的工具，如果使用得当，可以潜在地提高将科学证据纳入同期临床实践的速度。