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Chronic Disease Prevention:The Power of Public Health

By Dr. John Frank, Scientific Director,

CIHR-Institute of Population & Public Health

11th World Congress on Public Health Conference

August 2006

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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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Yach, D. et al. JAMA 2004;291:2616-2622.

Global Mortality From Chronic Diseases

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Yach, D. et al. JAMA 2004;291:2616-2622.

Deaths Attributable to 16 Leading Causes in Developing Countries, 2001

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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

1) Seek the root causes of disease and disability - a focus on determinants

2) Consider and deal with whole populations

3) Understand and apply the principles of social change, over the life course

Most Public Health Interventions

Health Outcomes

Most Health Care

Political Social Cultural Economic Spiritual Ecological Technological

Forces Nation-States

Regions

(Urban Entities)

Neighborhoods / Communities

Families / Couples / Households

Lifecourse of Individuals

Population Health Framework

Biological Endowment

Gene-Environment Interactions

Physical & Social Environmental Exposures

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The Bell-Curve Shift in Industrial Populations

Increasing Serum LDL Cholesterol & CHD Risk

% of Population

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..

Population – level factors

(largely environmental)

Individual(largely genetic

for CHD)

Source: Rose G. Sick Individuals and sick populations. 1985; Int J Epid 12:32-38.

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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

Environmental and

Policy Approaches

Educational,High Risk

and ClinicalPreventive Services

Approaches

Treatment

Upstream Downstream

Individually-orientedPopulation-oriented

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,19:379-416.

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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

Community-based interventions – Hype or Hope? (cont’d)

Source: Sorensen G., Emmons K, Hunt MK, Johnston D., 2003. Implications of the results of community intervention trials. Annu. Rev. Public Health,19:379-416.

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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