Federal guidance clarified that only a small subset of adverse events occurring in human research subjects are unanticipated problems that must be reported under 45 CFR part 46. The guidance helps ensure that the review and reporting of unanticipated problems occur in a timely, meaningful way so that the human subjects can be better protected from avoidable harms, while reducing unnecessary burden on IRB members. The vast majority of adverse events occurring in human subjects are not unanticipated problems, or alternatively put, are anticipated problems; a small proportion of adverse events are unanticipated problems; and unanticipated problems can include other incidents, experiences, and outcomes that are not adverse events.

In short, refer to page 2 of the "Reportable New Information" form located on the IRB website for the information that needs to be reported to the IRB.