Description

• Capacity:
  • Involves a clinical evaluation by a credentialed health care provider
  • Focuses on perceived ability of patient to participate and understand the process of informed consent
• Competence:
  • A legal determination of abilities, performed by a court judge
  • Refers executive functioning and ability to make decisions (i.e., finances, living wills)
    • Involves medical information but does not need to be limited to only medical issues
• Capacity is the currently preferred term to competence: legal capacity and medical capacity.
• A capacity determination is needed when arriving at a health care decision for testing, treatment, or an intervention involving risk of harm or no improvement.
  • Any treating health care provider can evaluate capacity, including the provider also obtaining informed consent (although a psychiatrist or neuropsychiatric consultant is often asked to weigh in, other health care providers can determine capacity).
• Medical capacity is determined by four elements:
  • Understanding risks and benefits of a procedure as well as alternatives
  • Appreciating those risks/benefits
  • Reasoning to make an informed decision
  • Communicating those informed decisions
    • Interviews with a guardian or designated health care power of attorney (POA) (if indicated)
• The four “Cs” of capacity are:
  • Context: comprehension of their health status
  • Choices: able to describe options
  • Consequences: able to explain possible outcomes
  • Consistency: continuity of choice selection
• Adequate cognition is a fundamental component but not the sole determinant of capacity (1).

Epidemiology

Most adults in the United States do not have an advanced directive—population studies show approximately 1/3 have completed an advanced directive (2).

Etiology and Pathophysiology

• Dementia is the most common reason individuals are found incapable of making health care decisions in the outpatient setting.
• Capacity is a dynamic state; reassessment is necessary with each significant health care decision and informed consent.

Risk Factors

• For incapacity:
  • Longevity, multiple comorbidities, hospitalized for medical reasons
  • Never married, never worked outside home
• Insufficient informed consent:
  • Patient factors:
    • Health illiteracy
    • Education level
    • Excessive information
  • Provider factors:
    • Inexperience with process (house staff for example)
    • Insufficient discussion time

General Prevention

Early assessment and periodic reassessment of capacity in:

• Dynamic patient conditions, like electrolyte imbalance, closed head injuries, delirium states
• After procedures with anesthesia or analgesics
• Enhancement and dissipation of mind-altering substances

Commonly Associated Conditions

• Dementia/Alzheimer disease, Parkinson disease, and traumatic brain injury
• Schizophrenia, depression, and substance abuse
• Acute illness, metabolic derangement