PURPOSE OF THE STUDY.
To identify clinical risk factors for asthma at 8 years of age in children with a history of infant wheeze.
From a population-based birth cohort of 4089 children born in Stockholm, Sweden, between 1994 and 1996, this analysis included 3251 (80%) who had data at years 1, 2, and 8 related to wheeze, eczema, rhinorrhea, and asthma.
Data were collected by questionnaires distributed at 2 months and 1, 2, 4, and 8 years of age. Infant wheeze was defined as ≥1 episodes of wheezing or whistling breathing sounds before age 2. Asthma at age 8 was defined as ≥4 wheezing episodes in the past 12 months or 1 wheezing episode in the past 12 months with either regular or intermittent use of inhaled corticosteroids.
Eight hundred twenty-three children (25%) in the analysis population met criteria for infant wheeze; 116 (14%) of infant wheezers had asthma at age 8, compared with 90 (4%) of infant nonwheezers. Among infants who wheezed, family history of atopy (adjusted odds ratio 1.53, 95% confidence interval 1.02–2.30), ≥3 episodes of wheeze (3.41, 2.09–5.56), wheezing that persisted through the first and second year (5.11, 2.51–10.41), use of inhaled corticosteroids (3.42, 2.20–5.32), and infant eczema (2.31, 1.52–3.49) were independent risk factors for asthma at age 8. Abdominal pain was also an independent risk factor for asthma at age 8; however, the potential mechanism for this finding was unclear. For infants who wheezed, having multiple risk factors was associated with an additional increase in the odds of having asthma at age 8.
Although infants who wheezed had an increased risk of asthma at school age compared with infants who did not wheeze, 86% of infants who wheezed did not go on to develop asthma at age 8. Among infants who wheezed, markers of atopy and severity of wheeze were risk factors for asthma at school age, findings that are consistent with previous studies.
Although infants who wheeze are at increased risk of asthma at age 8 compared with those without wheeze, overall, only 14% of those with infant wheeze went on to have asthma at school age, highlighting that recurrent wheeze is a poor predictor of asthma at school age. Better predictors of asthma are needed not only to provide better asthma anticipatory guidance to parents but also to be able to target appropriate populations for the development of primary prevention approaches.
- Copyright © 2015 by the American Academy of Pediatrics