Home Environmental Intervention in Inner-City Asthma: A Randomized Controlled Clinical Trial

Abstract

Eggleston PA, Butz A, Rand C, et al. Ann Allergy Asthma Immunol. 2005;95:518–524 PURPOSE OF THE STUDY. To conduct a randomized, controlled clinical trial to test the efficacy of home-based methods to reduce environmental pollutants and allergen exposure in the homes of asthmatic children living in an inner city. STUDY POPULATION. One hundred asthmatic children, ranging in age from 6 to 12 years, with physician-diagnosed asthma, current asthma symptoms, and no other chronic lung disease. METHODS. The families were randomly assigned to a treatment group that received intervention immediately (home-based education, cockroach and rodent extermination, mattress and pillow encasings, and a high-efficiency particulate air cleaner) or to a control group that received intervention at the end of the 1-year trial. In the treatment group, 84% received cockroach extermination, 70% received mouse extermination, and 75% used the air cleaner. Outcomes were evaluated against baseline by home evaluation at 6 and 12 months, clinical evaluation at 12 months, and multiple telephone interviews. RESULTS. Home particulate concentrations were lower at both 6 and 12 months in the treatment group. Home levels of particulate matter ≤10 μm declined by up to 39% in the treatment group as compared with an increase in the control group (P < .001), and cockroach-allergen levels decreased by 51% in the treatment group (P = .04). The proportion of symptomatic children increased in the control group and decreased in the treatment group, with significant differences seen at 6 months and later. In addition, children in the treatment group were significantly less likely to report daytime symptoms during the first 9 months compared with those in the control group. However, the mean difference in daytime symptoms over 12 months was only marginally significant (P = .07). Other measures of participant morbidity, such as nighttime symptoms, emergency department use, and spirometry findings, were not significantly changed during the study period. CONCLUSIONS. A tailored program of environmental and behavioral interventions to reduce indoor particulate matter and other relevant allergen levels in low-income, inner-city homes had a modest effect on asthma morbidity. REVIEWER COMMENTS. It is interesting to note that few of the 69% of the households with smokers in them changed smoking habits. Most likely, the environmental-control measures outlined in this article, implemented as part of a more comprehensive treatment plan including smoking cessation, could contribute more significantly to symptom reduction.