Vulnerable Adults in Research: From Consent to Assent?

Abstract

Introduction

Some scientific advances can become realities only with the help of vulnerable people who do not have legal capacity to consent to research. When dealing with legally non-competent adults, practitioners now consider the patient's own wishes more than ever before, and so they have pioneered the practice of seeking what has become known as their ‘assent’ before treating them. Assent has been defined as a person's ‘permission or affirmative agreement to something’. People who do not possess sufficient capacity to make a particular decision entirely on their own may nonetheless have certain psychological and cognitive abilities. Including such people in decisions that affect them directly but without necessarily handing the decision over to them completely, has had a certain moral appeal. Indeed, in many national and international guidelines on research using vulnerable populations, we see the widespread use of this new term, one apparently unsullied with the legal heritage of ‘consent’. In particular, the term ‘assent’ now appears separately from ‘consent’ in certain of these guidelines. For example, ‘assent’ has primarily and predominantly been used in research using children although in some significant documents, the term has been applied to any patient lacking capacity. For example, the World Medical Association's 2000 version of the Declaration of Helsinki states in Article 25: ‘When a subject deemed legally incompetent, such as a minor child, is able to give assent to decisions about participation in research, the investigator must obtain that assent in addition to the consent of the legally authorized representative.