More than 6 million American children under the age 18 have asthma . It is the third leading cause of hospitalization for children under 15 and the leading cause of chronic illness among children. While the incidence of asthma in children continues to grow nationally, it is rising at an alarming rate in the inner cities.

Inner-city children generally experience more severe disability from asthma and have more frequent hospitalizations. In addition, these children are commonly exposed to multiple substances, like tobacco smoke and cockroach allergens, that contribute to asthma exacerbations. (An allergen is a substance in the environment the triggers an allergic reaction, in this asthma.)

Asthma cannot be cured, but it can be managed by reducing a child’s exposure to the substances that trigger asthma attacks. Several studies have focused on reducing exposure to a specific allergen, such as tobacco smoke or cockroach allergens, but with little success. The Inner-City Asthma study published in the September 9, 2004 issue of the New England Journal of Medicine looked at whether a home-based, multi-faceted intervention, tailored to what a child is allergic to, could improve asthma-related outcomes in inner-city children.

About the study

The study looked at more than 900 inner-city children between the ages of 5 and 11 with moderate to severe asthma. At the beginning of the study, skin testing was done to determine a child’s specific environmental allergens. In addition, researchers evaluated each child’s home and collected dust from the child’s bedroom and tested for allergens. The children were then randomized to an intervention group or a control group.

For the intervention group, the researchers used the skin test results to design an individualized environmental intervention for each child. The caregivers were educated on how to limit exposure to specific allergens and other lung irritants, including dust mites, passive smoking, and cockroaches.

At the first visit, the caregivers in the intervention group were:

  • Taught about the role of allergens and irritants in the child’s asthma
  • Introduced to an environmental intervention plan, including the creation of an environmentally safe sleeping zone
  • Given allergen-reducing tools, including:
    • Covers for the child’s mattress, box springs, and pillows
    • Vacuum cleaner equipped with a high-efficiency particulate air (HEPA) filter
    • HEPA air purifier for the child’s bedroom
  • Provided professional pest control (for children allergic to cockroach allergen)

In addition, the investigators explained and demonstrated all allergen-reducing actions, and provided feedback and encouragement when the caregiver performed an action for the investigator. During the first 12 months of the study, the intervention group was visited at home an average of five times. Dust collections from the homes were conducted every 6 months during the two-year study.

The control group was visited at the onset of the study and at six-month intervals throughout the two years of the study. They were not given any additional education or allergen-reducing measures.

The findings

More than 78% of the children completed the two-year study. Researchers found that the children in the intervention group had, on average, 21 fewer days of asthma symptoms in the first year of the study compared to the control group. During the second or follow-up year, the intervention group had an average of 16 fewer days of asthma symptoms compared to the control group. Additionally, significant differences were seen just two months into the study and continued throughout the two years.

The intervention group had lower levels of cockroach and dust mite allergens in their bedrooms compared to the control group. This is important because the researchers found a relationship between the levels of allergens and asthma symptoms—the greater the reduction in allergens, the greater the reduction in symptoms.

The intervention group also experienced reductions in the amount of disruptions to caretaker’s plans, children and caretaker’s lost sleep, and missed school days.

How does this affect you?

This study’s intensive intervention resulted in fewer asthma symptoms, fewer missed school days, and fewer visits to the emergency department—reductions that are comparable to those seen with asthma inhalers.

The researchers estimate that the cost of the study intervention per child was between $1500 and $2000, or $750 to $1000 per year—similar to the cost of the most common asthma medications used to treat a child with moderately severe asthma. Although the initial cost of the intervention is significant, the benefits appear to be sustained over time, making the cost per year lower.

While reducing your child’s exposure to an allergen, such as passive smoke or dust, is a critical first step, it should not be the last one. Children with asthma are usually allergic to more than one substance. This study shows that several steps taken together can help improve your child’s asthma symptoms almost immediately and continue to over time. If your child has asthma, work with your doctor to determine what the allergens are and what you can do to help minimize your child’s exposure.