Certificates of confidentiality and unexpected complications for pragmatic clinical trials.

Formal guidance from the NIH is needed to address the application of CoCs to the setting of PCTs. In the meantime, it is essential for researchers designing and conducting PCTs, as well as health care systems in which this research is conducted, to be aware of the nuances inherent in CoCs so they can best adhere to their legal obligations regarding them. In the absence of guidance, special attention should be paid to pragmatic research that populates the electronic health record with research data as well as research conducted without explicit consent. Given the large amount of pragmatic research precipitated by the Coronavirus Disease 2019 pandemic, which has been accompanied by major efforts to share data, the need for such guidance is especially urgent.