Definitions: Health, Disability, Quality of Life These concepts are evolving, in line with our thinking about changing roles of the physician.

Conceptions of ‘health’ have broadened over time “Medical model” (absence of disease; anatomical integrity) Holistic model (adds mental & social function) Wellness or ecological models (functioning within an environment) Note: These conceptions can apply to health of individuals and to the health of populations Health as resource for coping with challenges

Examples of “medical model” definitions “Health is the absence of disease” Health is… "A state characterized by anatomic, physiologic and psychological integrity…” But: ‘Disease’ is no longer simple to define (how do you define hypertension? ‘Non-disease’ conditions; treatment products lead to redefining disease; …)

Medical conception of disease Diagnosis Therapy begun ‘Outcome’ (alive, dead, cured, etc) Symptoms appear Biological onset of disease Clinical Phase Preclinical Phase

Holistic definitions of health “A state of complete physical, mental and social well-being, and not merely the absence of disease or infirmity" (WHO, 1948)

Ecological definition “A sustainable state of equilibrium or harmony between humans and their physical, biological, and social environments that enables them to coexist indefinitely.” (Last J. Dictionary of Public Health. Oxford, N.Y., 2007) Themes: - Health as a quality of a group - Present & future state - Empowering

‘Health-as-a-resource’ 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." (WHO. Health promotion: a discussion document. Copenhagen, WHO, 1984)

Clarifying Disability WHO, 1976: Impairment Disability Handicap (International Classification of Impairments, Disability, & Handicap: ICIDH) WHO, 2001: Impairment Activity Participation (International Classification of Functioning: ICF)

Expanding conception of disease (2) Diagnosis Therapy begun ‘Outcome’ (alive, dead, cured, etc) Symptoms appear Biological onset of disease Clinical Phase Preclinical Phase ImpairmentDisabilityHandicap

How broad should we get? Physician roles widening to include advocacy, etc. What are the limits to this? What is the overall goal of medicine? Concept ‘quality of life’ borrowed from social sciences in the 1980s. Now used as outcome measure in clinical trials.

Definitions of Quality of Life “An essentially subjective judgment of the way people perceive themselves as contented and happy or otherwise, and able to function physically, emotionally, and socially” (J. Last, Dictionary of Public Health, 2007) “The degree to which a person enjoys the important possibilities of his or her life” (Centre for Health Promotion, U. of Toronto /09/17)

The expanding conception of disease (3) Diagnosis Therapy begun ‘Outcome’ (alive, dead, cured, etc) Symptoms appear Biological onset of disease Clinical Phase Preclinical Phase ImpairmentDisabilityHandicap Social Determinants Individual Risk factors Prevention Health Promotion Population Health

The Debate Continues Jadad and O’Grady. ‘How should health be defined?’ BMJ 2008; 337:a2900 BMJ Group blog: “ A global conversation on defining health: Alex Jadad and Laura O’Grady” jadad-on-defining-health/ jadad-on-defining-health/