In the Inner-City Asthma Study, families with children suffering from moderate-to-severe asthma received individualized in-home evaluation and education by environmental counselors to help them reduce allergens in the home. The study, conducted in the early 1990s on children with asthma ages five to 11 years living in seven inner-city neighborhoods across the country, proved successful: the level of allergens was lower in the homes of the families receiving the intervention, and the number of symptom-free days per child increased-34 additional days over the two-year study period.

But did the improvement in outcomes lower the overall costs? The cost of the program was $1,469 per family.

To find out, researchers calculated the costs of health care-resource use during the first intervention year and the one follow-up year. They found that the intervention group made significantly fewer unscheduled clinic visits and used significantly fewer [beta]-agonist inhalers than the control group but did not achieve cost savings.

Cost analysis estimated the cost of each symptom-free day to be $27.57. However, the health of children with moderate-to-severe asthma who received the intervention improved, and those children used fewer health care services. The study authors believe their cost estimates to be conservative and that their model was not able to measure all the benefits of the intervention. This study looked at direct health care costs to the one enrolled child over two years only. Benefits may have persisted beyond that time as well as improved the health of other family members.

Also, both the intervention and the control groups showed improvements in the number of symptom-free days. Because both groups were telephoned every two months by the research team to assess the child's asthma, the authors believe that the control group may have benefited from the reminder that those children were also being studied.

Additionally, the indirect costs associated with asthma-parents losing time from work and children from school-were not calculated.

Kattan M, et al. J Allergy Clin Immunol 2005;116(5):1058-63.

FIGURE. A recent study found that asthmatic children made fewer clinical visits-and used fewer [beta]-agonist inhalers-if allergens were reduced in their homes. A follow-up study found that the intervention did not result in cost savings, but the researchers say that many costs, such as a lost school day, could not be calculated.