Predictors for asthma at age 7 years for low-income children enrolled in the Childhood Asthma Prevention Study

Abstract

Objective: To identify the predictive factors of early childhood wheezing in children of low socioeconomic status.

Study design: The Childhood Asthma Prevention Study enrolled 177 low-income children (9-24 months old) with frequent wheezing. At age 7 years, presence of asthma was assessed through caregiver reports of physician diagnosis of asthma (CRPDA) and corroborated by assessment of bronchial hyperresponsiveness (BHR). Lung function, inflammatory markers, and asthma symptom severity were compared for children with ±CRPDA, ±BHR, and asthma. Baseline predictors for CRPDA, BHR, and asthma at 7 years of age were examined.

Results: Maternal symptom report strongly differentiated children with +CRPDA (49%) despite comparable airflow measurements (P < .0001), and spirometric lung function measurements were different for +BHR (65%) versus -BHR (P < .005). Univariate analyses revealed different baseline predictors of +CRPDA and +BHR for children at age 7 years. Higher levels of maternal psychological resources were associated with +CRPDA, but not +BHR. Only 39% of children with a history of frequent wheezing met the conservative definition of asthma at age 7 years, with the following significant predictors found: low birth weight, baseline symptom severity, and maternal psychological resources.

Conclusions: This low-income, multi-ethnic group of wheezing infants represents a unique population of children with distinct characteristics and risks for persistent asthma. Determination of asthma status at 7 years of age required objective measurement of BHR in addition to CRPDA. The association of maternal psychological resources with +CRPDA may represent a previously unrecognized factor in the determination of asthma status among low-income groups.