Klinnert MD, Price MR, Liu AH, Robinson JL. Pediatrics. 2003;112:49–57
Purpose of the Study.
Although information is available regarding wheezing and asthma among low-income, school-aged children, less is known about morbidity related to wheezing or asthma among infants and toddlers. The objective of this study was to evaluate biological, environmental, and psychosocial associates of morbidity in wheezing illness in a multiethnic sample of low-income infants <2 years of age.
A total of 177 infants, 9 to 24 months of age, and their families, recruited from pediatric departments of local hospitals and clinics in the metropolitan Denver area, were studied.
The protocol required the children to have had ≥3 health contacts with documented wheezing and to have undergone a complete evaluation as part of an environmental intervention program. Baseline evaluations of children included total immunoglobulin E level measurement, environmental assessment of tobacco smoke exposure, assay of urine samples for cotinine, psychosocial assessments (with the Rand Mental Health Battery) of anxiety, depression, positive effect, and emotion and stability of the caregiver, and assessment of health care utilization. Caregiver reports were included in the evaluation. At study entry, prior morbidity attributable to wheezing illness was assessed, primarily on the basis of caregiver reports and medical record documentation of hospitalizations and emergency department visits.
Of the infants in this study, 46% had ≥1 hospitalization and ∼60% had ≥2 emergency department visits from birth for treatment of wheezing conditions. Foreign-born Hispanic families took their infants to the emergency department significantly more than did other groups, including United States-born Hispanic families, white families, and black families, although they used fewer controller medications and documented lower illness severity. Overall, 72% of the children were receiving bronchodilators, whereas 28% were receiving controllers. The highest percentage of children receiving controller medications occurred in the white group. There was no relationship between receiving controller medications and experiencing ≥2 emergency department visits. Corticosteroid bursts were, however, associated with hospitalization (P < .001) and emergency department visits (P < .001). Multivariate analyses demonstrated 3 biological factors, namely, respiratory syncytial virus, elevated immunoglobulin E levels, and cockroach allergy in the home, that were independently associated with hospitalizations within this group. Emergency department visits were associated with caregivers with a status of single parent or smoker (P = .037 for single parent and P = .034 for smoker).
The authors concluded that ethnic and immigrant status played significant roles in morbidity related to infant wheezing illness. In addition to respiratory infection, allergic processes and social variables played roles, as evidenced by health care utilization.
Additional studies of this nature with larger populations, including suburban families, would be of interest to validate these findings. The relationships of ethnic, biological, and social factors to asthma morbidity are certainly consistent, however, with the paradigm of inner-city asthma that has been established for older children and adolescents.