Chronic Disease Prevention: The Power of Public Health

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Chronic Disease PreventionThe Power of Public
Health
11th World Congress on Public Health
Conference August 2006

• By Dr. John Frank, Scientific Director,
• CIHR-Institute of Population Public Health

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Presentation at a Glance

• Chronic Disease Prevention Challenges
• Selected examples
• What does the evidence tell us?
• Need for a population and public health approach

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Global Mortality From Chronic Diseases
Yach, D. et al. JAMA 20042912616-2622.
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Deaths Attributable to 16 Leading Causes in
Developing Countries, 2001
Yach, D. et al. JAMA 20042912616-2622.
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20-Year Trends in Smoking Current smokers by
age, Canada, 1981-2001 A Canadian Success Story
but.
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Age-Standardized Mortality Rates for
Cardiovascular Diseases, Canadian Males and
Females, 1950-1999.
Source Health Canada, 2003. Age-standardized
to the 1991 Canadian population.
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Source 2004 CPHI report, Improving the Health
of Canadians.
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Source 2004 CPHI report, Improving the Health
of Canadians.
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Renewing our Public Health Principles

• Seek the root causes of disease and disability -
  a focus on determinants
• Consider and deal with whole populations
• Understand and apply the principles of social
  change, over the life course

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Population Health Framework
Political Social Cultural Economic Spiritual
Ecological Technological
Health Outcomes
Forces
Nation-States
Regions
(Urban Entities)
Neighborhoods / Communities
Most Health Care
Families / Couples / Households
Lifecourse of Individuals
Biological Endowment
Physical Social Environmental Exposures
Gene-Environment Interactions
Most Public Health Interventions
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The Bell-Curve Shift in Industrial Populations
In Western industrialized populations, the entire
bell-curve of risk-factor levels is shifted due
to dietary and other lifestyle factors, so even
low levels within the population confer CHD
risk. Thus a large number of people at small
risk give rise to more cases of disease than the
small number who are at high risk..
? of Population
Individual (largely genetic for CHD)
Population level factors (largely environmental)
?
?
Increasing Serum LDL Cholesterol CHD Risk?
Source Rose G. Sick Individuals and sick
populations. 1985 Int J Epid 1232-38.
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The Importance of Population Distributions of
Exposure
Source The World Health Report 2002.
Reducing Risks, Promoting Healthy Life. Chapter
2, Figure 2.3
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Action on Obesity Three Different Paradigms
Compliments of PHRED program
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Community-based interventions Hype or Hope?

• Usually suffer from methodological and conceptual
  limitations - poor study design, lack of
  evaluation, theoretical basis is limited given
  complexity of interactions
• Small or modest effect sizes at the individual
  level vs. what was expected, especially given
  other social trends

Source Sorensen G., Emmons K, Hunt MK, Johnston
D., 2003. Implications of the results of
community intervention trials. Annu. Rev. Public
Health,19379-416.
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Community-based interventions Hype or Hope?
(contd)

• Interventions targeted only at individual-level
  knowledge, attitude and behaviour cannot succeed
  alone
• Should therefore not be seen as the panacea to
  solving complex societal problems, especially
  given duration and intensity of such
  interventions and the countervailing forces
  arraigned against them

Source Sorensen G., Emmons K, Hunt MK, Johnston
D., 2003. Implications of the results of
community intervention trials. Annu. Rev. Public
Health,19379-416.
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BUT THERE IS HOPE.

• Impacts can be realized if community-based
  interventions
• Are properly resourced and sustained over time
• Community-led, addressing the social and cultural
  context in which individual behaviours are
  manifested
• Are complemented by comprehensive
  population-level interventions that address
• Environmental supports/controls
• Economic levers
• Enforcement (regulations / legislation)
• Research funding agencies need to put more
  emphasis on supporting policy and program
  intervention research

Source Smedley BD and Syme SL (eds.).
Promoting Health Intervention Strategies from
Social and Behavioral Research. Washington
National Academy of Sciences, 2000.
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Calling for Sustainable Investmentsin the
Public Health System the Champion for
Upstream Thinking

• Our focus on the (sick-)care system problems
  needing urgent attention should not detract us
  from our responsibility to invest in public
  health.
• More is needed to strengthen the front-line where
  most of public health takes place
• Community-level creativity must be tapped to
  change social norms local public health
  professionals working in intersectoral coalitions