Definitions: Health, Disability,
Quality of Life
These are abstract concepts, so there is no
single and permanent way to define, and
hence to measure, them.
The definitions are open to discussion and so
have evolved over time.
Here is an overview of how our thinking has
changed.
Definitions of ‘health’ have
broadened over time
Medical model (≈ anatomical integrity)
Holistic model (adds mental & social function)
Wellness or ecological models (functioning within an environment)
Hold this thought:
These can apply to health of individuals
and to the health of populations
1. Medical Definitions:
two examples
• “Health is the absence of disease”
• Health is… "A state characterized by anatomic,
physiologic and psychological integrity; ability to
perform personally valued family, work and
community roles; ability to deal with physical,
biologic, psychological and social stress..."
(Stokes J. J Community Health 1982;8:33-41)
Medical Conception of Disease
Preclinical
Phase
Biological
onset of
disease
Clinical Phase
Symptoms
appear
‘Outcome’
(alive,
Therapy
dead,
begun cured, etc)
Diagnosis
2. Holistic Definitions
• “A state of complete physical, mental and
social well-being and not merely the
absence of disease or infirmity"
(WHO, 1948)
3a. Wellness Definitions
•
"The extent to which an individual or group is
able to realize aspirations and satisfy needs, and
to change or cope with the environment. Health
is a resource for everyday life, not the objective
of living; it is a positive concept, emphasizing
social and personal resources, as well as
physical capacities."
(Health promotion: a discussion document. Copenhagen, WHO,
1984)
3b. Ecological Definition
“A sustainable state in which humans and
other living creatures with which they
interact can coexist indefinitely, in
equilibrium.”
(Last J. Dictionary of epidemiology. Oxford, N.Y., 2001)
Clarifying Disability
WHO, 1976:
Impairment
Disability
Handicap
(International Classification of Impairments, Disability, &
Handicap: ICIDH)
WHO, 2001:
Impairment
Activity
Participation
(International Classification of Functioning: ICF)
Quality of Life
• In the grand debate between the narrow model of
medicine (to treat an illness) and the broad (to restore
function), what is the overall goal?
• Some answered in terms of enhancing well-being, but
this has a connotation of material & economic wealth,
which fall outside the ambit of medicine.
• Another issue was that heroic medical interventions
sometimes caused adverse effects, so there was a need
for an overall criterion that balanced the harms and
benefits of therapy.
• In the 1980s, medicine seized on the term ‘quality of life’
(which had been lying around the social sciences for
years).
• It is generally defined in terms of being able to function in
desired social roles, even if you have a health problem,
and relies on the subjective perception of the patient.
Health at the Population Level
• The previous ideas referred to individuals: your
main future work, but we can also think of the
health of populations.
• This is either merely the average of the health of
individuals (e.g. how many had a heart attack
last year?). This is “health in the population”,
• Or it could refer to the health of the population
as a whole: is it a caring society? Are people’s
rights respected? Does the system function
well: do things get fixed on time? This is “health
of the population” and it is relevant to the
physician’s role as health advocate.