If a subject's involvement in a study can lead to harm, what is the most effective action regarding informed consent?

The most effective action regarding informed consent in a situation where a subject's involvement in a study may lead to harm is to obtain a waiver of documentation of informed consent. This approach is appropriate when certain criteria are met, for instance, if obtaining consent in the traditional manner could increase risks to the participants, or if the research involves minimal risk to the subjects and the rights and welfare of the subjects are not adversely affected.

A waiver of documentation allows for the ethical conduct of research while still addressing the need for participant protection. In cases where the standard informed consent process might compromise participant safety or where it may not be feasible to maintain the standard procedure (for example, in emergency situations or where obtaining consent could cause distress), having this waiver clearly enables the researcher to proceed. It maintains the integrity of the study while upholding ethical standards.

The other options, such as ensuring documentation remains accessible, conducting the study without consent, or informing subjects post-participation, either do not appropriately address the potential risks to participants or could potentially violate ethical standards set by IRBs.