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Setting definitions of childhood asthma in epidemiologic studies
Author(s) -
Silva Diana,
Severo Milton,
Paciência Inês,
Rufo João,
Martins Carla,
Moreira Pedro,
Padrão Patrícia,
Delgado Luís,
Moreira André
Publication year - 2019
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.13111
Subject(s) - medicine , asthma , exhaled nitric oxide , concordance , epidemiology , spirometry , gold standard (test) , pediatrics , physical therapy
Abstract Background The definitions of childhood asthma differ among epidemiological studies. We aimed to compare the diagnostic accuracy and agreement of previous asthma definitions and to evaluate questionnaire‐driven asthma definition patterns. Methods Data on 808 participants aged 7‐12 years from 20 schools were analyzed. Asthma definitions based on symptoms assessed by questionnaire, parent‐reported medical asthma diagnosis, current use of asthma medication, airway reversibility after bronchodilatation, and increased (≥35 ppb) levels of exhaled nitric oxide (eNO) were compared with a gold standard (medical diagnosis of asthma with asthma symptoms in the past 12 months and/or airway reversibility). Concordance was assessed by Cohen's kappa. Data‐driven analysis was applied to the questionnaire, and six scores were determined “asthma,” “rhinitis,” “cough,” “non‐specific respiratory symptoms,” “treated asthma,” and “uncontrolled asthma.” Tree decisions were built using these scores. Results Definitions of asthma based on respiratory symptoms, airway reversibility, and parent‐reported medical diagnosis had a low sensitivity but high specificity. Agreement between reported and objective measures was poor. Parent‐reported medical asthma diagnosis, but not reversibility or eNO, was able to predict questionnaire‐driven symptom patterns. Decision trees indicated that those with recent non‐specific respiratory symptoms had a higher probability of positive bronchodilation. Conclusion A standardized operational definition of asthma should include a composite score based on reported asthma medical diagnosis, symptoms, and lung function.