Comparison of 3 Indices for Assessing the Severity of Bronchial Asthma Exacerbations in Children

Background: The modified pulmonary index score (mPIS) is reported to be useful for assessing bronchial asthma severity. However, mPIS has not been compared with other scores to date. In this study, we have compared mPIS with other scores and clarified the usefulness of mPIS. Materials and Methods: The study assessed children (n = 67; median age = 3 years) hospitalized for acute exacerbation of bronchial asthma without pneumonia between April 2016 and August 2017. We evaluated mPIS, pulmonary index score (PIS), and modified Wood's Clinical Asthma Score (mWCAS) from their medical record at admission, and we retrospectively evaluated the correlation between each score and clinical outcomes. Results: The median values for mPIS, PIS, and mWCAS were 9, 7, and 3, respectively. The median durations of hospitalization and of systemic glucocorticosteroid therapy were 7 and 4 days, respectively; 27 patients (40.2%) received continuous inhalation therapy with isoproterenol. All the scores were moderately positively correlated with the duration of hospitalization as follows: mPIS, 0.566 (P < 0.001); PIS, 0.488 (P < 0.001); and mWCAS, 0.411 (P < 0.001). Moderate positive correlations were observed between all scores and the duration of systemic glucocorticosteroid therapy as follows: mPIS, 0.488 (P < 0.001); PIS, 0.407 (P < 0.001); and mWCAS, 0.367 (P = 0.002). Receiver operating characteristic curve analysis of need for continuous inhalation therapy with isoproterenol yielded areas under the curve of 0.91, 0.83, and 0.87 for mPIS, PIS, and mWCAS, respectively. Conclusions: Correlation of mPIS and outcome was equal to or stronger than that of PIS or mWCAS, and mPIS can be useful for assessing the severity of acute exacerbations of bronchial asthma and predicting prognosis.