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Asthma Predictive Index (API)
Predicts likelihood of persistent childhood asthma in young children with recurrent wheezing.
Asthma Predictive Index (API)
Major: a parent with physician-diagnosed asthma
Major: physician-diagnosed atopic dermatitis (eczema)
Minor: physician-diagnosed allergic rhinitis
Minor: wheezing episodes apart from (unrelated to) colds
Minor: peripheral blood eosinophilia >=4%
ResultAPI negative
Negative index: most children with a negative index do not go on to have active asthma at school age.
- Major criteria met
- 0
- Minor criteria met
- 0
When to use
- Children under 3 years with recurrent wheezing (>=4 episodes in the past year, with at least one physician-confirmed), to gauge the probability of persistent/school-age asthma.
Formula
API is positive if the child has >=1 major criterion (parental asthma, physician-diagnosed atopic dermatitis) OR >=2 minor criteria (physician-diagnosed allergic rhinitis, wheezing apart from colds, peripheral blood eosinophilia >=4%).
Pearls and pitfalls
- Derived from the Tucson Children's Respiratory Study birth cohort; a positive loose index was associated with roughly a 4- to 10-fold increase in the odds of active asthma at ages 6-13 compared with a negative index.
- A negative index has a high negative predictive value, useful for reassuring families that persistent asthma is unlikely.