What is informed consent?

The Belmont Report analyses consent into three elements: information, comprehension and voluntariness. Under the 2024 Declaration of Helsinki (paragraph 26), candidates must be told, in plain language, about aims and methods, benefits and risks, funding, conflicts of interest, privacy protections and compensation for harm. The person seeking consent must ensure the information was understood, and the candidate decides without coercion or undue influence and may withdraw at any time without reprisal.

Beyond these three elements, the person giving consent must have decisional capacity. CIOMS describes decisional capacity as the ability to understand material information, appreciate the situation and its consequences, consider the options and communicate a choice, and says people should be considered capable unless shown otherwise. For adults who lack capacity, a legally authorized representative gives permission and the person’s assent is sought; for children and adolescents, a parent or representative gives permission and the child’s assent is sought (Guidelines 16 and 17).

CIOMS treats consent as a two-way process, with the signed form as its record in the general case. A waiver or modification is possible only with research ethics committee approval, and Guideline 10 names three conditions: the research would not be feasible without it, it has important social value, and it poses no more than minimal risk.