Practicability & the "three-pronged" consent strategy for secondary research
Of the five criteria IRBs consider in waiving informed consent, it is often "practicability" that is most challenging.
The commonly accepted definitions of the term "practicable" are (a) feasible;
(b) capable of being effected, done or put into practice; and (
c) that may be practiced or performed; capable of being done or accomplished
with available means or resources.
The practicability criterion is more than deciding whether obtaining informed consent is practicable. The criterion states, "that the research could not be practicably carried out without the waiver". In other words, it wouldn't be practicable to do the research if consent were required. Scenarios included in the SACHRP letter include cases where scientific validity would be compromised or ethical concerns would be raised if consent were required.
However, in some cases, practicability justifications include barriers that aren't always insurmountable. In these instances, a multifaceted approach may be appropriate. The IRB approves the waiver on the condition that the investigator 1) attempt to obtain the subject's consent , 2) attempt to obtain consent from the legally authorized representative (LAR), and 3) document all attempts. This demonstrates due diligence in respecting individual rights and welfare.
Generally, the "three-pronged" approach should be limited to secondary research with information or specimens collected for a different primary purpose. And with variations in context of the research, population, personnel role, and other nuances, each waiver request should be reviewed on a case-by-case basis.
