Modified Asthma Predictive Index (mAPI) Calculator

How does this modified asthma predictive index (mAPI) calculator work?

This health tool aims to predict a future diagnosis of acute asthma in children of school years based on respiratory and allergic criteria present at age three or younger.

Not only applicable in the case of young children (below 3 years old) but also only for pediatric patients with four or more episodes of wheezing per year, the compulsory criteria to be met before any further use of the mAPI.

The other major and minor criteria are presented below:

■ API major criteria:

- Family history (parent) with asthma;

- Patient diagnosed with eczema (atopic dermatitis);

- Diagnosed sensitivity to allergens in the air (demonstrated through positive skin prick tests or blood tests to a series of allergens such as dust mites, molds, weeds etc.).

■ API minor criteria:

- Wheezing present apart from colds;

- Greater than 4% blood eosinophils;

- Diagnosed food allergies (i.e. milk, eggs, peanuts).

The mAPI is validated when the four or more wheezing episodes per year criteria is checked AND at least one major OR at least two minor criteria are met.

The following table summarizes the sensitivity and specificity values for predictions in patients aged 3 in the study group.

This model follows the standardized asthma predictive index (API). One of the limitations is represented by the fact that its predictive capacity depends on the prevalence of asthma in the general population.

Asthma predictive indices

Indices such as the one presented in the mAPI calculator, are useful in delineating the probable asthma diagnosis prediction from the 40% wheezing presence in the first year of life (considered normal) and subsequent 30% recurrent wheezing in children at the age of 6.

At a glimpse, the main difference between the original API and the modified version consists in the addition of another minor criteria, that concerning the presence of diagnosed food allergies.

This comes as a recognition of the fact that allergic sensitization to aeroallergens and foods in early life has been associated with development of asthma at school age.

There are also other differences, in terms of which criteria is major or minor, the choice of recurrent wheezing episodes per year, as well as the resulting prediction specificities.

Comparison table between API and modified API:

At the moment, API is still preferred to the modified version in the case of longitudinal studies.

Further studies are trying to find means of employing API and mAPI in clinical studies with pharmaco-clinical methods of preventing the predicted diagnosis of asthma.

References

1) Chang TS, Lemanske RF, Guilbert TW, Gern JE, Coen MH, Evans MD, Gangnon RE, Page CD, Jackson DJ. (2013) Evaluation of the Modified Asthma Predictive Index in High-Risk Preschool Children. J Allergy Clin Immunol Pract; 1(2): 10.1016.

2) Castro-Rodríguez JA, Holberg CJ, Wright AL, Martinez FD. (2000) A clinical index to define risk of asthma in young children with recurrent wheezing. Am J Respir Crit Care Med; 162(4 Pt 1):1403-6.

3) Guilbert TW, Morgan WJ, Zeiger RS, Mauger DT, Boehmer SJ, Szefler SJ, Bacharier LB, Lemanske RF Jr, Strunk RC, Allen DB, Bloomberg GR, Heldt G, Krawiec M, Larsen G, Liu AH, Chinchilli VM, Sorkness CA, Taussig LM, Martinez FD. (2006) Long-term inhaled corticosteroids in preschool children at high risk for asthma. N Engl J Med; 354(19):1985-97.

4) Leonardi NA, Spycher BD, Strippoli MP, Frey U, Silverman M, Kuehni CE. (2011) Validation of the Asthma Predictive Index and comparison with simpler clinical prediction rules. J Allergy Clin Immunol; 127(6):1466-72.