Prevention of Illness

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Prevention of Illness

• Fundamental Concepts

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• Striking a reasonable balance between cure and
  prevention would do a great deal to optimize the
  health status of Canadians.Spending 5 of health
  care dollars on prevention isnt a balance
• Marions corollary

• In nature, the optimum is almost always in the
  middle somewhere. Distrust assertions that the
  optimum is at an extreme point. Akin's Laws of
  Spacecraft DesignDave Akin, Professor,
  University of Maryland

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Why Focus on Prevention?

• A significant percentage of global mortality and
  morbidity is caused by preventable conditions
• The WHO estimates that 30 of global mortality
  results from 10 risk factors, all of which are
  preventable (The World Health Report, 2000)

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• The list includes
• Childhood and maternal under nutrition
• Underweight
• Vitamin mineral deficiencies
• Lack of breast feeding

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• Other diet physical activity related factors
• High blood pressure
• High cholesterol
• Obesity, overweight, high body mass
• Low fruit vegetable intake
• Physical activity

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• Sexual Reproductive Health
• Unsafe sex
• Lack of contraception
• Addictive Substances
• Smoking oral tobacco use
• Alcohol
• Illicit drugs

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• Environmental Risks
• Unsafe water, sanitation hygiene
• Urban air pollution
• Indoor smoke from solid fuels
• Lead exposure
• Climate change

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• Occupational Risks
• Injuries
• Exposure to carcinogens
• Airborne particulates
• Ergonomic stressors
• Noise

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• An American study identifies 9 modifiable risk
  factors that constitute the leading causes of
  death in the US (Mokdad et al. (2000). Actual
  causes of death in the United States, 2000. JAMA
  291(10), 1238-1245)
• Tobacco (18.1 of total deaths)
• Poor diet and physical activity (16.6) (soon to
  overtake tobacco)
• Alcohol (3.5)
• Microbial agents

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• Toxic agents
• Motor vehicle crashes
• Firearms
• Sexual behaviours
• Illicit use of drugs

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• Unfortunately, these lists are not the same
• Makes direct comparison impossible
• However, some important themes emerge from these
  two studies
• What are they?

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• One important insight conveyed by these studies
  is that there is more than one way to
  conceptualize causes of death (mortality) and
  illness (morbidity)
• These studies represent a relatively new approach
  to this subject

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• A more traditional approach is reflected in how
  Canadian mortality is generally reported by
  Statistics Canada
• In 1997 the leading causes of death in Canada for
  both sexes, all ages were

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• Diseases of the circulatory system
• Cancer
• Respiratory diseases
• Unintentional injuries
• Diseases of the digestive system
• Endocrine diseases
• Diseases of the nervous system
• Mental disorders
• Suicide
• Genito-urinary diseases

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• There are problems with this more traditional
  approach to analyzing mortality
• 1. It fails to reveal that there are important
  age and sex differences in human mortality

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• For example, the leading cause of death for all
  Canadians, both male and female aged 65 is
  diseases of the circulatory system
• But for 15-19 year old males females, its
  unintentional injuries
• For 25-34 year old males, its still injuries
• For 25-34 year old females, its cancer

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• An effective approach to prevention requires an
  understanding of the risks to health that affect
  the specific population you are working with

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• 2. Traditional approaches tend to focus on
  pathology, not what underlies the pathology
• This leads research in a particular direction
• Biomedical
• Emphasis on individual clients
• Treatment

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• Refocusing on underlying causes shifts the
  research agenda to
• Prevention
• Identification of modifiable risk factors
• Sometimes a focus on lifestyle/behaviour
• Hopefully also an emphasis on social
  environmental risks to health

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• 3. Many underlying causes of mortality
  morbidity have social, economic political
  origins
• e.g. poverty
• This reality is not reflected in traditional
  epidemiological approaches to assessing the
  health of populations

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• Easier to discern in studies that search for
  underlying causes and modifiable risk factors
• This course will emphasize risk and how risk can
  be modified at the level of
• -the individual
• -the community

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• It will place at least as much emphasis on social
  and political change as it does on changing
  individual behaviour

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Health

• Health can be conceptualized in many ways
• How one defines health shapes how one sets about
  attaining it
• This is the primary message of Chapter 5
  Concepts of Health

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• Young Higgins identify two ways to define
  health (and there are many, many more)
• Medically
• Systems
• Each approach leads to a different set of
  conditions that determine health

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• Several approaches to the idea of determinants of
  health will be covered in this course
• Like definitions of health, all tend to highlight
  different aspects of what influences human health

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Prevention Vs. Health Promotion

• Theoretical distinctions between these two
  concepts are quite clear

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Health Promotion

• Strategies that enable or enhance the achievement
  of optimal health
• Cause-effect relationship not relevant

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• Main characteristics Statchenko Jenicek (1996)
• Positive, multi-dimensional model
• Participatory
• Aimed at and seeks changes in populations
  environment (social, political, physical)
• Involves a network of issues
• Uses diverse complementary strategies
• Facilitating, enabling
• Multi-sectoral

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Prevention

• Interventions that discourage the interaction of
  an individual, group or population with an agent
  known to produce harm
• Cause-effect relationship known

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• Main characteristics Statchenko Jenicek (1996)
• Absence of disease
• Medical model
• Aimed at and seeks change in high risk groups
• Concerned about specific pathology
• Often one-shot strategies
• Employs directive/persuasive strategies
• Situated primarily in health care sector

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• Do these distinctions hold up in practice?