1- Serviço de Imunoalergologia, Hospital de Dona Estefânia, Centro Hospitalar de Lisboa Central, EPE, Rua Jacinta Marto, 1169-045, Lisbon, Portugal
2- CEDOC, Respiratory Research Group, Nova Medical School, Campo dos Mártires da Pátria, 130, 1169-056, Lisbon, Portugal
Reunião internacional - 2016th European Academy of Allergy and Clinical Immunology. Apresentado sob forma de poster
Resumo: Introduction: According to GINA poorly controlled asthma is associated with greater variability in lung function than well controlled asthma. Excessive variability may be identified by a reversibility test which is routinely performed regardless of the baseline FEV1 value. There is a lack of data regarding which baseline spirometric parameters could better discriminate patients with a positive bronchodilator response.
Aim: We aimed to assess the accuracy of the baseline FEV1 percent predicted value (FEV1%) and FEV1/FVC ratio, in discriminating patients with a positive bronchodilator response. Additionally, we aimed to determine the optimal cut-off value of baseline FEV1% and FEV1/FVC ratio for a positive bronchodilator test.
Methods: We conducted a cross-sectional retrospective study that included pediatric patients (6-17 years) assessed in our department by spirometry and bronchodilator test, from January 2013 to June 2015. A positive bronchodilator response was considered if there was a 12% improvement of the FEV1 after bronchodilator. Accuracy and optimal cut-off values were studied by ROC analysis, for baseline FEV1% (Global Lung Initiative – GLI – 2012 reference equations) and FEV1/FVC ratio.
Results: We included 362 patients, with a mean age of 12.6 years (SD: 2.9), predominantly male (68%). The mean FEV1% and FEV1/FVC ratio were 96.3% (SD: 14.4%) and 0.81 (SD: 0.08), respectively. FEV1% presented an AUC of 0.76 and its best discriminative value was 88.4% (sensitivity of 56.5% and specificity of 83.3%). For FEV1/FVC ratio the AUC was 0.89 and its optimal cut-off value was 0.78 (sensitivity of 83.7% and specificity of 84.1%).
Conclusions: In our sample, the FEV1/FVC ratio was more accurate than FEV1% to discriminate patients with a positive bronchodilator test. In pediatric patients with a FEV1/FVC ratio above 0.78 the non-execution of the bronchodilator test might be considered.
Palavras Chave: Asthma, Pediatric, Bronchodilator Cut-off