Morbidity patterns among low-income wheezing infants.

Objective: This study describes morbidity attributable to wheezing illness in a multi-ethnic sample of low-income infants younger than age 2, and examines biological, environmental, and psychosocial correlates of morbidity indexes.

Method: Infants 9 to 24 months old, considered at risk for developing asthma on the basis of having had 3 or more health care contacts with documented wheezing, received comprehensive evaluations as part of an environmental intervention study. Baseline evaluations with the infants, their families, and their home environments focused on biological, environmental, and psychosocial factors that would potentially increase asthma risk for the children. At study entry, prior morbidity attributable to wheezing illness was assessed with caregiver reports of symptom frequency and severity and medication use, caregiver quality of life, and medical record documentation of hospitalizations and emergency department (ED) visits.

Results: Forty-six percent of the infants had 1 or more hospitalizations and 59% had 2 or more ED visits since birth for wheezing illness. Foreign-born Hispanic families had significantly more ED visits for their children's wheezing illness than US-born Hispanic families, whites, or blacks, although they used fewer controller medications and they reported less illness severity. Multivariate analyses showed 3 biological factors, respiratory syncytial virus, elevated child IgE, and cockroach allergen in the home, were independently associated with hospitalizations within this sample. Similar analyses showed that ED visits were not associated with biological variables, but rather with caregivers with single parent status and smokers. Caregiver reports of wheezing illness severity were correlated with ED visits, but not with hospitalizations. Severity ratings were higher for children of mothers with asthma and for those whose caregivers had higher anxiety and stress. The only correlate of caregiver ratings of poor quality of life was high caregiver anxiety.

Conclusions: Ethnic and immigrant status was an important factor in morbidity attributable to infant wheezing illness. In addition to respiratory infection, both allergic processes and social variables were associated with morbidity as measured by health care utilization. Caregiver reports of illness severity were significantly correlated with psychosocial factors.