To present an interim analysis of the effect of a home-based intervention with low-income caregivers of wheezing infants at risk for childhood asthma on mediating variables.
Infants aged 9 to 24 months with 3 or more physician-documented wheezing episodes were randomly assigned to environmental support intervention (ES) (n = 90) or control (n = 91) groups. Nurse home visitors intervened for 1 year to decrease allergen and environmental tobacco smoke exposure and improve symptom perception and management. Assessments at baseline and 12 months included allergens in house dust, infant urinary cotinine levels, caregivers’ symptom reports, quality of life, illness management, and quality of caregiving. Medical records were coded for hospitalizations, emergency department visits, and corticosteroid bursts.
Within the ES group, cockroach allergen levels were significantly reduced and there was a trend toward reduction in dog dander levels. Among infants with detectable urinary cotinine, levels were significantly reduced in the ES group. Caregiver psychological resources modified the impact, and low-resource ES caregivers were the most strongly affected. Asthma knowledge and provider collaboration improved significantly in the ES group. Neither reports of infant symptoms nor emergency department visits or hospitalizations showed positive intervention effects. Number of corticosteroid bursts for infants was significantly higher for the ES group.
The Childhood Asthma Prevention Study intervention was effective in reducing several environmental exposures and improving illness management. However, even with an intensive home-based intervention, we failed to reduce respiratory symptoms or medical use in the ES group relative to the control group, illustrating the difficulty of changing the course of early asthma development among low-income infants.