Assessment Instruments of Decision-Making Capacity

Capacity to consent to informed treatment decisions is an often overlooked, yet tremendously critical, aspect of modern medical practice. Despite its importance, research has shown that clinicians often fail to identify patients who lack capacity. Currently, other than a clinical psychiatric consultation and evaluation, there is no standardized method for determining whether a patient has capacity to make treatment decisions. Cognitive scales, such as the MMSE, may inform capacity evaluations but are neither sensitive nor specific. Accordingly, various clinical instruments have been developed to aid in the determination of capacity to consent to treatment. This is a review of several of these instruments. While there is no convincing evidence for the use of a particular scale, the CQ and ACE are easy to administer and can be efficiently utilized by clinicians to inform capacity assessment. While more time consuming to administer and score, the MacCAT-T also provides a comprehensive evaluation of key capacity domains.