Baltimore Asthma Intervention
Trial
Patrick N. Breysse, PhD
Professor and Director Division of Environmental Health
Engineering
Department of Environmental Health Sciences
Johns Hopkins Bloomberg School of Public Health
Associate Director
Center for Childhood Asthma in the Urban Environment
Centers for Children’s Environmental Health
Co sponsored by NIEHS, EPA, CDC
Johns Hopkins Center for the
Asthmatic Child in the Urban
Environment (CCAUE)
Director: Peyton A. Eggleston, MD
Associate Director: Patrick Breysse, PhD
Investigators
Tim Buckley, PhD
Gregory Diette, MD, MS
Sukon Kanchanaraska, PhD
Jerry Krishnan, MD
Elizabeth Matsui, MD
Sekhar Reddy, PhD
Arlene Butz, RN, DSc
Cynthia Rand, PhD
Marsha Wills-Karp, PhD
Steve Georas, MD
Why Focus on Asthma?
• In 1999…
–
–
–
–
–
–
–
–
–
10,488,000 persons with asthma in US (3.8%)
14.5 million work days lost with asthma
3,114,000 children < 14 yrs old with asthma (4.9%)
14 million lost school days
14.6% report activity limited by asthma
10,808,000 physician visits
1,997,000 ER visits for acute asthma
478,000 hospitalizations for asthma
4657 deaths
CDC MMWR March 29, 2002 / 51(SS01);1-13
CCAUE
• Multidisciplinary research center
• Combine basic research and community
based studies
• Long Term Goals
– Understand mechanism by which allergens,
pollutant increases airway inflammation and
asthma morbidity
– Develop effective intervention strategies
Environmental Factors in Urban
Asthma Research Model
IMMUNOLOGIC
SENSITIZATION
ALLERGENS
AIR
POLLUTANTS
CHILDREN LIVING
IN URBAN
ENVIRONMENTS
ASTHMATIC
AIRWAY
OBSTRUCTION
RESPIRATORY
MORBIDITY
SUSCEPTIBILITY FACTORS
ATOPY, INFLAMMATION CONTROL
BRONCHIAL HYPERRESPONSIVENESS
UNDERLYING SOCIAL SUSCEPTIBILITY FACTORS
POVERTY, STRESS, CONFLICTING NEEDS, EDUCATION, ADHERENCE, ACCESS TO CARE
CCAUE Study Components
• Community Based Studies
– Cohort Study of Environmental Asthma
• Longitudinal comparison of environmental exposures and
other risk factors
• Greg Diette et al.
– Asthma Susceptibility to Particulates, Allergens
• Genetic association of environmental exposures and asthma
• Greg Diette et al.
– Asthma Intervention Trial
• Randomized trial to reduced household exposures to
particulate matter and allergens
• Peyton Eggleston et al.
CCAUE Study Components
• Basic Biologic Research
– Genetics of Response to Ozone
• Mouse model examining genetic basis of Ozone and
endotoxin inflammation
• Sekhar Reddy, Steve Kleeberger
– Inflammatory Response to Particulate Matter
• Mouse model comparing susceptible and non-susceptible
strains
• Compare indoor and outdoor particulate matter
• Marsha Wills-Karp
– Dendritic Cell Response to Particulate Matter
• In vitro response of cultured dendritic cells
• Steve Georas
CCAUE Community Outreach
• Community Advisory Committee
– 9 members representing political
organizations, schools, churches, parents
• Advisory Functions
– Protocol feasibility
– Community priorities, concerns
– Translation of results to local community
387 children enrolled in
asthma education
program
180 eligible and
interested
Recruitment
93 ineligible
44 refused
13 ineligible
42 refused or
unable to contact
125 consented,
questionnaire completed
6 refused or
unable to contact
116 baseline home
evaluation
16 failed
scheduled visits
3 moved out of
area
100 randomized
97 competed
1 year study
3 dropped out of
study
CCAUE – Asthma Intervention
Study
• Randomized Controlled Trial of Home Exposure Control
in Asthma
• Rationale
– Strong epidemiologic evidence that indoor
environmental exposure relates to asthma morbidity
– Effective treatments available for indoor
environmental exposure
• Goal
– Test hypothesis that reduction of allergen and pollutant
exposure in the homes of asthmatic children will reduce
morbidity
STUDY AREA
Air monitoring station
Recruitment Plan
• 100 children recruited from elementary
schools in inner city neighborhoods
• Eligibility:
– 6 – 12 years old
– Doctor-diagnosed asthma
– Current asthma symptoms
– No other lung disease
– Live in catchment area
Intervention Protocol
INTERVENTION
TREATMENT
BASELINE
TREATMENT
CONTROL
questionnaire
skin test
serum,FEV1
home
environment
telephone
0
3
6
9
12
Intervention
• 3-4 home visits by home health educators
• Roach extermination, sealed plastic
containers
• Allergen-proof bedding encasings
• HEPA air cleaner in child’s bedroom
• Smoking cessation education and support
Air Cleaner
Environmental Monitoring
• Indoor Air Pollutants were measured over
a 72-hr period in child's bedroom
– Particulate Matter
• PM10
• PM2.5
• Data-logging Nephelometer
– Ozone
– Nitrogen Dioxide
– Airborne nicotine (marker for passive smoking
exposure)
In-Home Air Sampling Set-Up
0
23:51:30
22:04:30
20:17:30
18:30:30
16:43:30
14:56:30
13:09:30
11:22:30
09:35:30
07:48:30
06:01:30
04:14:30
02:27:30
00:40:30
22:53:30
21:06:30
19:19:30
17:32:30
15:45:30
13:58:30
12:11:30
10:24:30
08:37:30
06:50:30
05:03:30
03:16:30
01:29:30
23:42:30
1.2
21:55:30
20:08:30
18:21:30
16:34:30
PM Conc (mg/m3)
Comparison of Indoor, Outdoor at the Home, and
Outdoor Central Site Particulate Matter
1.4
Outdoor
Indoor
Central Site
1
0.8
0.6
0.4
0.2
Reservoir Dust Allergen Samples
• Vacuum samples collected in bedroom,
living room/family room, and kitchen
– Analyzed for
•
•
•
•
•
Cockroach
Dust mite
Cat
Dog
Mouse
Baseline Characteristics
Age (mean)
home ETS (%)
Cockroach (%)
Pos skin test (%)
Mod/severe syx (%)
controller meds (%)
FEV1 (% pred)
ED visit/3 mon (%)
CONTROL
8.3
65
66
65
20
34
94±21
36
TREATMENT
8.5
73
62
75
28
28
101±20
32
Housing Characteristics
Characteristic
%
Characteristic
%
Row House
91
Leaks in bedroom
18
Roof Leaks
24
Food in bedroom
29
Cats
26
Cockroaches in bedroom
8
Dogs
20
Mouse droppings in
bedroom
7
Current smoker
46
Moisture damage in kitchen
22
Cockroaches in kitchen
31
Mouse droppings in kitchen
38
Median Particulate Concentrations
g/m3
(median)
PM10
PM 2.5
PM 10
PM 2.5
60
50
treatment
treatment
control
control
40
30
20
10
0
baseline
6 mon
12 mon
Particulate Concentrations:
% Change
% change from baseline
20
10
0
-10
p=0.08
PM10
PM 2.5
PM 10
PM 2.5
treatment
treatment
control
control
-20
p<0.001
-30
p=0.019
-40
p<0.001
-50
baseline
6 months
12 months
Bedroom Cockroach Allergen
Bla g 1
U/gm
Treatment
Control
10
p=0.07
p=0.001
1
base
6 mon
12 mon
Change in proportion with symptoms
Proportion of children with wheeze, cough,
dyspnea in last 2 weeks
p=<0.001
40
Control group
30
20
p=0.60
p=<0.001
10
p=0.02
0
-10
-20
Treatment group
-30
-40
base
3 mon
6 mon
9 mon
12 mon
Other Health Outcomes
• Other health outcomes not different
between the two groups
– Nighttime symptoms
– ED visits
– Hospitalizations
– FEV1
Summary
• A global environmental intervention was
able to reduce levels of PM10, PM2.5 and
cockroach allergen in inner city homes
• There was an associated reduction in
symptoms in asthmatic children living in
the homes
• Persistence of reduction is uncertain
Acknowledgements
• In addition the investigators previously
mentioned
– Chris Beck
– D’Ann Williams
– Jean Curtin-Brosnan
– Lee Swartz
– Barry Merriman
– Karen Callahan
-
Nowella Durkin
Mayme Grant
Craig Lewis
Jennette Logan
Zina Nettles-Smith
Dena Scott