Discriminative properties of two predictive indices for asthma diagnosis in a sample of preschoolers with recurrent wheezing

Introduction: It is important to predict if preschool children with recurrent wheezing will suffer from asthma in future years. To aid in this early identification, a number of asthma predictive scores have been reported, such as the asthma predictive index (API) and the PIAMA risk score. However, to the best of our knowledge, their predictive properties have not been evaluated in any lower- to middle-income country.

Materials and methods: A prospective cohort study was carried out including preschoolers aged 1-3 years with recurrent wheezing who came to our Pediatric Pulmonary Unit in Bogota, Colombia. We collected the information required to complete the API index and the PIAMA risk score. At 5-6 years of age, the patients were contacted in order to determine if they were suffering from active asthma. We calculated the sensitivity, specificity, predictive values, and likelihood ratios (LR) of the API and PIAMA risk scores for the presence of active asthma at 5-6 years old.

Results: The mean age at recruitment of the 130 included patients was 27.2 ± 5.9 months. The loose API yielded a sensitivity of 71.4% (95% CI: 50.0-86.2), specificity of 33.3% (95% CI 23.5-44.8), and positive predictive value of 23.8% (95% CI: 15.0-35.6). The stringent API yielded a sensitivity of 42.9% (95% CI: 24.5-63.5), specificity of 79.2% (95% CI 68.4-86.9), positive predictive value of 37.5% (95% CI: 21.2-57.3), and positive LR of 2.06. The PIAMA risk score yielded a sensitivity of 54.5% (95% CI: 42.6-66.0), specificity of 78.9 (95% CI: 66.7-87.5), positive predictive value of 75.0 (95% CI: 61.2-85.1), and positive LR of 2.59.

Conclusions: Our results suggest that both indices can be used to predict asthma in preschoolers with recurrent wheezing in the context of a referral hospital.