Evaluation of the Modified Asthma Predictive Index in High-Risk Preschool Children

BACKGROUND: Prediction of subsequent school-age asthma during the preschool years has proven challenging. OBJECTIVE: To confirm in a post hoc analysis the predictive ability of the modified Asthma Predictive Index (mAPI) in a high-risk cohort and a theoretical unselected population. We also tested a potential mAPI modification with a 2-wheezing episode requirement (m(2)API) in the same populations. METHODS: Subjects (n = 289) with a family history of allergy and/or asthma were used to predict asthma at age 6, 8, and 11 years with the use of characteristics collected during the first 3 years of life. The mAPI and the m2API were tested for predictive value. RESULTS: For the mAPI and m2API, school-age asthma prediction improved from 1 to 3 years of age. The mAPI had high predictive value after a positive test (positive likelihood ratio ranging from 4.9 to 55) for asthma development at years 6, 8, and 11. Lowering the number of wheezing episodes to 2 (m(2)API) lowered the predictive value after a positive test (positive likelihood ratio ranging from 1.91 to 13.1) without meaningfully improving the predictive value of a negative test. Posttest probabilities for a positive mAPI reached 72% and 90% in unselected and high-risk populations, respectively. CONCLUSIONS: In a high-risk cohort, a positive mAPI greatly increased future asthma probability (eg, 30% pretest probability to 90% posttest probability) and is a preferred predictive test to the m(2)API. With its more favorable positive posttest probability, the mAPI can aid clinical decision making in assessing future asthma risk for preschool-age children. (C) 2013 American Academy of Allergy, Asthma & Immunology.