Published Online: November, 2014
While asthma symptoms may begin during the first five years, the condition is difficult to diagnose accurately until after age 6-7. For this reason, medical researchers have attempted to develop inexpensive and accurate tools for predicting risk of asthma as early as three years of age. The purpose of this study was to evaluate the capacity of persistent wheezing and a novel asthma predictive index (API)—the University of Cincinnati Asthma Predictive Index (ucAPI)—both determined at age 3 to predict objectively confirmed asthma at age 7.
Recently published in The Journal of Allergy and Clinical Immunology: In Practice, this study was conducted by Amin and colleagues using the Cincinnati Allergy and Air Pollution birth cohort study, in which 589 children born to atopic parent(s) were recruited shortly after birth and clinically evaluated annually from ages 1-4 and at age 7. “Persistent wheezing” was defined as 2 or more episodes of wheezing in the previous year at both ages 2 and 3. The ucAPI, adapted from previously reported APIs, was defined at age 3 by: 2 or more wheezing episodes in the previous 12 months; and 1 of 3 major criteria (parental asthma, a positive skin test to 1 or common aeroallergens, or history of eczema), or 2 of the 3 minor criteria (wheezing without a cold, physician-diagnosed nasal allergy, or positive skin test to milk or egg). Asthma was diagnosed at age 7 either by: 1) parent reported symptoms or physician diagnosed asthma confirmed by objective lung function tests; or 2) prior treatment for asthma with daily asthma controller medications.
After adjusting for other relevant predictors of asthma, children with a positive ucAPI at age 3 were 13 times more likely to develop asthma at age 7. Children with persistent wheezing at age 3 were almost 10 times more likely to develop asthma at age 7. The ucAPI was the most sensitive predictive index evaluated at age 3, identifying 44% of children who would develop asthma at age 7. Of children with a positive ucAPI at age 3, 60% were identified with asthma at age 7. Of children with persistent wheezing at age 3, 61% had asthma at age 7.
These results confirm the usefulness of early clinical predictor indices of asthma such as the API for identifying young children at risk for later development of asthma. These investigators demonstrated that the ucAPI and persistent wheezing at age 3 as defined in this study are clinically useful tools for predicting future asthma in school-age children. This study was the first to show that the ucAPI is a good predictor of objectively confirmed childhood asthma.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.