When a volunteer suffers a health problem during a clinical study, researchers should make sure the problem is unusual or troubling before reporting it to an institutional review board, the Food and Drug Administration urged in draft guidelines issued on Monday.

Institutional review boards, which consist largely of faculty volunteers, are responsible for evaluating the risks and benefits of experiments involving human subjects. Researchers are required to send the boards reports of unexpected health problems among the subjects of a study, called “adverse-event reports,” so the boards can continuously evaluate each study’s safety.

The draft guidelines are a response to years of complaints from the review boards that they often become overwhelmed with a flood of adverse-event reports that lack necessary context or explanation. The guidelines discourage researchers from submitting the reports when health problems are isolated and do not appear to represent a pattern of serious risk unexpected in the study. —Josh Keller