Patient understanding: How should it be defined and assessed in clinical practice?

In order for patients to make autonomous decisions in a healthcare setting, they must understand relevant information. There is, however, a lack of consensus on how understanding should be defined or assessed in this context, despite the fact that in practice doctors are regularly required to judge whether a patient has understood medical information. Current accounts of patient decision-making often focus on the information which needs to be disclosed to the patient to support their autonomous decision-making. Far less attention has been afforded to questions about how we might determine whether a patient has understood the information disclosed to them. Theoretical approaches to the concept of understanding in this context, and practically useful frameworks for assessing it, are lacking. In this paper, I use a number of hypothetical clinical situations to explore the conditions that are required for a patient to adequately understand information in medical decision-making. Drawing upon the wider philosophical literature, I propose a number of criteria which are necessary for understanding in a medical context: patients must (1) grasp a body of information which (2) reasonably reflects a responsible body of medical professionals' best estimate of the truth, (3) to a degree which meets a context-specific threshold. These criteria may be helpful in guiding assessments of patient understanding in clinical practice.