Comparison on the profiles of a modified Borg scale and the pediatric dyspnea scale during an induced bronchoconstriction in children with clinical asthma

ABSTRACT

PURPOSE: Dyspnea is the cardinal symptom of asthma, but it is difficult to quantify clinically. Although modified Borg (mBorg) scale has been successfully used in adult, but there has been some difficulties to apply in children. Recently, Pediatric Dyspnea Scale (PDS) was adequately designed and has been widely used. The aim of this study is to compare 2 evaluating scales of dyspnea provoked by induced-bronchoconstriction in childhood asthma. METHODS: Seventy-three clinically suspected children with asthma were enrolled in this study. Each ‘fractional exhaled nitric oxide (FeNO)’ was documented. Forced expiratory volume in 1 second (FEV₁), mBorg score and PDS score were recorded during methacholine provocation test. RESULTS: Mapping using canonical plot demonstrated global similarity between 2 scales with some distinctive features. Whereas mBorg score showed more diverse categories in low level of dyspnea, PDS score did in medium level of it. A distribution of dyspnea perception score at a 20% decrease in FEV₁ relative to baseline (PS₂₀), a perception score of dyspnea at 20% fall in FEV1 of 2 scales represented similar wide, biphasic feature. Statistical relevance was verified with spearman correlation (R(s)=0.903, P<0.001) and Bland-Altman analysis. PS₂₀ of both scores and FeNO had no statistical relationship. While relationship between PS20 by mBorg score and the concentration of methacholine at 20% fall in FEV₁ (PC₂₀) was not significant (R(s)=0.224, P=0.154), that between PS₂₀ by PDS and PC₂₀ was weak positive (R(s)=0.29, P=0.063). CONCLUSION: PDS had similar pattern to assess the dyspnea with the mBorg scale suggesting adequacy of PDS in evaluating pediatric clinical asthma. We expect these scales to help clinical practice in complementary ways.