April 6 -8, 2004

Asthma in California: Challenges in Assessment and Intervention

Shanghai-California Environmental Health Conference

Richard Kreutzer, M.D.California – China Environmental

Health Training Program

April 6 -8, 2004

Lifetime Asthma Prevalence by Period (Survey Year)

0

2

4

6

8

10

12

14

16

1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Period (survey year)

% li

feti

me

asth

ma

Asthma in California

Asthma in California-Lifetime Prevalence

April 6 -8, 2004

Age by Cohort

0

5

10

15

20

25

<1910 1910-19 1920-29 1930-39 1940-49 1950-59 1960-69 1970-79 1980+

birth cohort (year born)

% li

feti

me

asth

ma 18-24

25-34

35-44

45-54

55-64

65-74

75+

Asthma in California-Cohort Analysis

April 6 -8, 2004

Definition of Asthma

• A chronic inflammatory disorder of the airway

• Infiltration of mast cells, eosinophils and lymphocytes

• Recurrent episodes of wheezing, coughing and shortness of breath

• Widespread, variable and often reversible airflow limitation

• Airway hyperresponsivenessSlide 1

April 6 -8, 2004

Magnitude of the Problem

• 150 million asthmatics world wide

• Prevalence increasing in most countries (20 to 50% every 10 years)

• Significant cause of school/work absence

• Health care expenditures very high

• 1 million unnecessary deaths each decade

Slide 3

April 6 -8, 2004

Cost of Illness

• Hospital Stay

• Intensive Care

• Emergency Department

• Primary Care

• Medications

Direct Medical Care

• Social Security

• Lost work output

• Lost school days

• Impact on individual/family/society

Indirect Costs

Slide 5

April 6 -8, 2004

What is the cause of asthma?

April 6 -8, 2004

Mechanisms Underlying the Definition of Asthma

Risk Factors(for development of asthma)

AirwayHyperresponsiveness

Airflow Limitation

SymptomsRisk Factors

(for exacerbation)

Slide 2

April 6 -8, 2004

Risk Factors for Asthma

• Asthma occurs in families

• Atopy: The strongest identifiable risk factor for the development of asthma

• Allergen and chemical sensitizer exposures

• Contributing factors may increase susceptibility to development of asthma in predisposed individuals

Slide 6

April 6 -8, 2004

Risk Factors that Lead to Asthma Development

• Atopy• Family history

Predisposing Factors

• Indoor Allergens– Domestic Mites and cockroach– Animal Allergens– Tobacco smoke– Fungi

• Outdoor Pollution/Allergens– Ozone– Pollens

• Occupational Sensitizers

Causal Factors

• Respiratory Infections

• Small Size at Birth

• Diet

• Exercise

• Cold air

• Air Pollution/allergens– Outdoor Pollutants– Indoor Pollutants

• Smoking– Passive Smoking– Active Smoking

Contributing Factors

Slide 7

April 6 -8, 2004

Factors Influencing the Rise in Asthma

Lifestyle Changes

Immune System Changes

Slide 8

April 6 -8, 2004

Role of “Western” Lifestyle

• Increase in indoor furnishings

• Humidity and indoor temperature

• Decreased ventilation

• Increased time indoors

• Reduction in physical activity can result in allergic sensitization and “priming” for asthma development

• Hygiene hypothesis

Slide 10

April 6 -8, 2004

Factors Influencing Atopy

Slide 9

April 6 -8, 2004

Immune System Balance in Asthma Development

Slide 11

April 6 -8, 2004

Influences on the Developing Immune Response

Inheritance of a genetic susceptibility to atopy

Effect of the in utero environment created by the mother (diet, allergen exposure, etc.)

Maternally directed development of the fetal immune response to common environmental antigens

Actions of early infections, gut microbial flora colonization and allergen exposures of the infant on the developing immune

response after birth

Development of a normal or allergic immune response (and symptoms) to common environmental antigens

1st trimester of pregnancy

2nd and 3rd trimester of pregnancy

Birth

1st year of life

British Medical Bulletin 2000;56(No.4) Slide 12

April 6 -8, 2004 Slide 13

April 6 -8, 2004 Slide 14

April 6 -8, 2004

Asthma Management Issues

• Disease management model versus addressing the ecology of the disease

• Clinical approach versus a population-based approach

• What are the places in the community where changes can influence the course of asthma?

April 6 -8, 2004

Management by Management by PatientPatient

Management by Management by PatientPatient

Family InvolvementFamily InvolvementFamily InvolvementFamily Involvement

Clinical ExpertiseClinical ExpertiseClinical ExpertiseClinical Expertise

Work/School SupportWork/School SupportWork/School SupportWork/School Support

Community Awareness, Support & ActionCommunity Awareness, Support & ActionCommunity Awareness, Support & ActionCommunity Awareness, Support & Action

Community-Wide Environmental Control MeasuresCommunity-Wide Environmental Control MeasuresCommunity-Wide Environmental Control MeasuresCommunity-Wide Environmental Control Measures

Conducive PoliciesConducive PoliciesConducive PoliciesConducive PoliciesNoreen Clark

April 6 -8, 2004

PlacePlacePlacePlace

LocationLocationLocationLocation

PurposePurposePurposePurpose

Physical InfrastructurePhysical InfrastructurePhysical InfrastructurePhysical Infrastructure

Policies/PracticesPolicies/PracticesPolicies/PracticesPolicies/Practices

Multiplicity of UsersMultiplicity of UsersMultiplicity of UsersMultiplicity of Users

Governance and Governance and EnforcementEnforcement

Governance and Governance and EnforcementEnforcement

16

April 6 -8, 2004

April 6 -8, 2004

April 6 -8, 2004

Social Environment Stressors

Physical Environment Stressors

Health Outcomes

Intervening Factors

Amy Schulz, et.al.

Stress Process Model

April 6 -8, 2004

Potential Places for Intervention

• Clinics and health care institutions

• Home

• Preschool

• School

• Workplace

• Community- e.g. energy, agriculture, transportation, planning and zoning

April 6 -8, 2004

Strategic Plan for Asthma in California

April 6 -8, 2004

Strategic Plan for Asthma in California – Five Goals

• Research, epidemiology, and evaluation

• Public education

• Treatment and management

• Secondary prevention

• Policy

April 6 -8, 2004

Overcoming barriers:Integration across organizations

April 6 -8, 2004

To conclude:

• Integration is a powerful tool to extend current resources and develop new ones.

• Integration doesn’t come easily but there are effective strategies to help get there.

• Paths to integration will vary by community and must fit the local landscape.