The Borg scale is accurate in children and adolescents older than 9 years with cystic fibrosis.

OBJECTIVE To evaluate the accuracy of the modified Borg scale to estimate lung impairment, measured via FEV(1) in children and adolescents with cystic fibrosis. METHODS This cross-sectional prospective study was conducted with cystic fibrosis patients, 6-18 y old. With the modified Borg scale we evaluated their subjective perceptions of dyspnea before and after submaximal exercises, and its correlation with lung function (spirometry), 6-min walk test (6MWT), and nutritional status according to body mass index. RESULTS Forty-one patients (mean +/- SD age range 11.1 +/- 4.1 y), were included in the study. The median (and interquartile range) modified Borg scale score after 6MWT was 2 (1-3). The mean percent-of-predicted FEV(1) (FEV(1)%) was 97 +/- 32%. The Z score of the 6MWT distance (6MWTZ) for 61% of the patients was < or = -2. The modified Borg scale correlated weakly with the other variables when all patients in the sample were analyzed. There was a significantly greater correlation of the Borg-scale score with FEV(1)% (r = -0.59, P = .003) and with 6MWTZ (r = 0.46, P = .03) when patients older than 9 years were evaluated separately. The receiver operating characteristic curve analysis revealed that a modified-Borg-scale cut-off point of 2.5 generated an area of 0.80, a sensitivity of 80%, a specificity of 77%, and an accuracy of 0.78 to predict FEV(1)% lower than 80% in the group of patients older than 9 years. CONCLUSIONS The modified Borg scale is accurate to assess the subjective perception of dyspnea of children older than 9 years and adolescents with cystic fibrosis.