| Customized Program Reduces Asthma-Related Illness in Inner-City Children
A program that reduces allergens and tobacco smoke in the home
resulted in fewer asthma-related illnesses in children participating
in the intervention than in those who were not, according to a new
study sponsored by the National Institutes of Health (NIH). Children
taking part in the intervention had 21 fewer days of asthma-related
symptoms over the 1-year course of intervention.
The study co-funded by the National Institute of Allergy and Infectious
Diseases (NIAID) and the National Institute of Environmental Health
Sciences (NIEHS), two NIH institutes appears in the September 9th
issue of The New England Journal of Medicine.
"The burden that childhood asthma places on our society is
enormous accounting for roughly 14 million missed school days each
year and $3.2 billion per year in treatment," says Anthony
S. Fauci, M.D., director of NIAID. "This important research
will provide long-term practical benefits to the millions of children
who live with asthma in the form of better quality of life, fewer
emergency room visits and hospitalizations and lower healthcare
"These study results are exciting because they show that changes
made in the home environment can produce a reduction in symptoms
comparable to that achieved with asthma inhalers," notes Kenneth
Olden, Ph.D., director of NIEHS.
Asthma, a chronic lung disease characterized by coughing, wheezing
and difficulty breathing, affects roughly 20 million Americans.
However, children who live in the inner city in particular African-American
and Hispanic children suffer disproportionately from the disease.
Elevated asthma-related illness in this population may stem from
exposure to high levels of multiple indoor allergens and tobacco
More than 900 children ages 5 to 11 with moderate to severe asthma
participated in the study. Each participant had to be allergic to
at least one common indoor environmental allergen, such as cockroach
allergen or mold. The children, most of whom were African American
or Hispanic, lived in low-income sections of seven major metropolitan
areas the Bronx, Boston, Chicago, Dallas, New York City, Seattle/Tacoma
and Tucson. Once accepted into the study, they were randomly assigned
to either the intervention group or a control group.
Based on the child's sensitivity to the selected indoor allergens,
investigators designed an individualized environmental intervention,
carried out by the child's mother or another caretaker. The intervention
focused on educating the family about ways to reduce or eliminate
all allergens to which the child was allergic, as well as to reduce
exposure to tobacco smoke, and motivating them to pursue these steps.
The investigators developed separate interventions tailored to tobacco
smoke and to the following allergens house dust mite, cockroach,
pet, rodent and mold.
In addition, families were given specific allergen-reducing measures,
such as allergen-impermeable covers for children's bedding and air
purifiers with HEPA (high efficiency particulate air) filters, to
be placed in key locations within their homes, including the children's
bedrooms. Cockroach extermination visits were provided for children
who were allergic to cockroach allergens. During the first year
of the study, the investigators conducted educational home visits
with the families in the intervention group. Throughout the yearlong
study and the one-year follow-up, researchers closely monitored
all participants' asthma symptoms and home allergen levels.
Children who participated in the intervention had significantly
fewer asthma symptoms compared with those in the control group:
an average of 21 fewer days of symptoms in the first year and an
average of 16 fewer days during the second, or follow-up, year.
In addition, the benefits of the intervention occurred rapidly:
Investigators noted significant reductions in symptoms just 2 months
after the study began.
The levels of cockroach and dust mite allergens in the children's
bedrooms in the intervention group were substantially lower than
in the control group. Furthermore, the researchers noted a direct
correlation between allergen levels and asthma symptoms for the
children in the intervention group: The greater the drop in cockroach
or house dust mite allergen levels, the greater the reduction in
asthma symptoms, suggesting that the allergy-reducing measures not
the educational visits made the difference.
Most previous environmental intervention studies that have focused
on controlling a single allergen or tobacco smoke exclusively, have
met with limited success.
"Children with asthma are usually sensitive to more than one
allergen," says Daniel Rotrosen, M.D., director of NIAID's
Division of Allergy, Immunology, and Transplantation. "By taking
a multifaceted, home-based approach, this new study demonstrates
the promising results families can achieve when they incorporate
the recommended practices of allergen reduction into their everyday
The Inner City Asthma Study, a cooperative, multicenter study comprising
seven centers across the country, is an outgrowth of the National
Cooperative Inner-City Asthma Study, which ended in 1996. The principal
investigator of the study is Wayne J. Morgan, M.D., University of
Arizona College of Medicine, Tucson.
NIAID and NIEHS are components of the National Institutes of
Health, an agency of the U.S. Department of Health and Human Services.
NIAID supports basic and applied research to prevent, diagnose and
treat infectious diseases such as HIV/AIDS and other sexually transmitted
infections, influenza, tuberculosis, malaria and illness from potential
agents of bioterrorism. NIAID also supports research on transplantation
and immune-related illnesses, including autoimmune disorders, asthma
NIEHS conducts and supports research to reduce the burden of
human illness and dysfunction from environmental causes by understanding
environmental factors, individual susceptibility and age, and by
discovering how these influences interrelate.
News releases, fact sheets and other NIAID-related materials are
available on the NIAID Web site at http://www.niaid.nih.gov.
Reference: W Morgan et al. Results of a home-based environmental
intervention in urban children with asthma-The Inner City Asthma Study.
The New England Journal of Medicine 351(11): XX-XX (2004).