Background The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) risk score predicts the probability of having asthma at school age among preschool children with suggestive symptoms. Objective We sought to externally validate the PIAMA risk score at different ages and in ethnic and socioeconomic subgroups of children in addition to updating it. Methods We studied 2877 children with preschool asthma-like symptoms participating in the multiethnic, prospective, population-based cohort study Generation R. The PIAMA risk score was assessed at preschool age, and asthma was predicted at age 6 years. Discrimination (concordance index [C-index]) and calibration were calculated. The PIAMA risk score was updated, and its performance was similarly analyzed. Results At age 6 years, 6% (168/2877) of the children had asthma. The discriminative ability of the original PIAMA risk score to predict asthma in Generation R was similar compared with that in the PIAMA cohort (C-index = 0.74 vs 0.71). The predicted risks by using the original PIAMA risk score for having asthma at the age of 6 years tended to be slightly higher than the observed risks (8% vs 6%). No differences in discriminative ability were found at different ages or in ethnic and socioeconomic subgroups (P >.05). The updated PIAMA risk score had a C-index of 0.75. Conclusions The PIAMA risk score showed good external validity. The discriminative ability was similar at different ages and in ethnic and socioeconomic subgroups of preschool children, which suggests good generalizability. Further studies are needed to reproduce the predictive performance of the updated PIAMA risk score in other populations and settings and to assess its clinical relevance.

Additional Metadata
Keywords Asthma, birth cohort, children, external validation, prediction, Prevention and Incidence of Asthma and Mite Allergy risk score, prognosis, updating, wheeze
Persistent URL dx.doi.org/10.1016/j.jaci.2013.07.007), hdl.handle.net/1765/101498
Journal Journal of Allergy and Clinical Immunology
Grant This work was funded by the European Commission 7th Framework Programme; grant id fp7/229571 - Respiratory Science Promoted by International Research Exchanges (RESPIRE), This work was funded by the European Commission 7th Framework Programme; grant id fp7/241604 - Developing a Child Cohort Research Strategy for Europe (CHICOS)
Citation
Hafkamp-De Groen, E.H.D, Lingsma, H.F, Caudri, D, Levie, D. (Deborah), Wijga, A.H, Koppelman, G.H, … Raat, H. (2013). Predicting asthma in preschool children with asthma-like symptoms: Validating and updating the PIAMA risk score. Journal of Allergy and Clinical Immunology, 132(6). doi:10.1016/j.jaci.2013.07.007)