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Spirometry‐adjusted fraction of exhaled nitric oxide increases accuracy for assessment of asthma control in children
Author(s) -
Martins Carla,
Silva Diana,
Severo Milton,
Rufo João,
Paciência Inês,
Madureira Joana,
Padrão Patrícia,
Moreira Pedro,
Delgado Luís,
Oliveira Fernandes Eduardo,
Barros Henrique,
Malmberg Pekka,
Moreira André
Publication year - 2017
Publication title -
pediatric allergy and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.269
H-Index - 89
eISSN - 1399-3038
pISSN - 0905-6157
DOI - 10.1111/pai.12803
Subject(s) - exhaled nitric oxide , spirometry , medicine , asthma , receiver operating characteristic
Spirometry and exhaled nitric oxide are two important complimentary tools to identify and assess asthma control in children. We aimed to determine the ability of a new suggested spirometry‐adjusted fraction of exhaled nitric oxide ( NO ) index in doing that. A random sample of 1602 schoolchildren were screened by a health questionnaire, skin prick tests, spirometry with bronchodilation and exhaled NO . A total of 662 children were included with median ( IQR ) exhaled NO 11(14) ppb. Receiver operating characteristic ( ROC ) curves using exhaled NO equations from Malmberg, Kovesi and Buchvald, and spirometry‐adjusted fraction of exhaled NO values were applied to identify asthmatic children and uncontrolled asthma. Receiver operating characteristic ( ROC ) curves failed to identify asthmatic children (all AUC < 0.700). Spirometry‐adjusted fraction of exhaled NO / FEV 1 ( AUC = 0.712; P = .010) and NO / FEF 25%‐75% ( AUC = 0.735 P = .004) had a fair and increased ability to identify uncontrolled disease compared with exhaled NO ( AUC = 0.707; P = .011) or the Malmberg equation ( AUC = 0.701; P = .014). Sensitivity and specificity identifying non‐controlled asthma were 59% and 81%, respectively, for the cut‐off value of 9.7 ppb/L for exhaled NO / FEV 1 , and 40% and 100% for 15.7 ppb/L/s for exhaled NO / FEF 25%‐75% . Exhaled NO did not allow to identify childhood asthma. Spirometry‐adjusted fraction of exhaled NO performed better‐assessing asthma control in children. Thus, although more validation studies are needed, we suggest its use in epidemiological studies to assess asthma control.