Background. Assessment of capacity plays a pivotal role
in determining when decisions need to be
made on behalf of an individual. It therefore has major clinical management
implications for health
care professionals and civil liberties implications for the person concerned.
In many countries, there
is a presumption that adults have the capacity to make health care decisions.
However, in persons
with a mental disability, capacity may be temporarily or permanently impaired.Methods. A selective review is presented which considers:
(i) the broad approaches taken to
determining capacity; (ii) the abilities commonly assessed in
determining capacity; and (iii) the
principles underlying health care decision-making for adults who are without
capacity.Results. Capacity is a functional concept, determined by the
person's ability to understand, retain,
and weigh up information relevant to the decision in order to arrive at
a choice, and then to
communicate that choice. We have reviewed the studies that examined decision-making
abilities in
people with dementia, chronic mental illness or intellectual disabilities.
Approaches to
decision-making in adults who lack capacity include: anticipatory decisions
made through advance health
care statements or decisions by proxy based on ‘best interests’
or ‘substituted judgement’.Conclusions. The understanding of clinical and legal aspects
of capacity is still developing. This
paper examines current concepts of capacity and decision-making on behalf
of those without
capacity. We propose a framework, in line with current ethical and legal
guidelines, as an aid to
clinicians when they are seeking consent for a health care intervention.
Capacity to make health care decisions: its
importance in clinical practice
