Predictive value of bronchial diastolic response test in adult patients with chronic cough suspected as cough variant asthma
Objective To explore the value of bronchial diastolic response(BDR)test in pre-dicting the cough variant asthma(CVA)in patients with chronic cough or negative result of BDR test.Methods A total of 140 patients with chronic cough and negative result of BDR test were se-lected and treated with inhaled corticosteroids(ICS)and long-acting β2-agonists for 4 weeks,and their lung functions were detected before and after treatment.Receiver operating characteristic(ROC)curve was used to evaluate the predictive values of the forced expiratory volume in the first second as a percentage of predicted value(FEV1%),exhaled nitric oxide(FeNO),forced expirato-ry flow at 25%to 75%(FEF25%to75%)and forced expiratory flow rate in 25%to 75%(FEF%25%to75%)alone or their combined diagnosis.Results After treatment,there were 98 cases diagnosed as negative for CVA and 42 cases diagnosed as positive for CVA.In combination of evalua-tion indexes,the top three combinations for CVA diagnosis were FEF%25%to 75%+△FEV1%,FEF25%to75%+FeNO,and △FEV,+△FEV1%.Venn diagram of the combined prediction showed that there was an overlap in CVA positive diagnostic patients with FeNO ≥41.50 × 10-9 mol/L,△FEV1%≥5.90%,and FEF%25%to 75%≤61.99%.Conclusion After treatment,patient's show-ing FeNO ≥41.50 × 10-9 mol/L,△FEV1%≥5.90%and FEF%25%to 75%≤61.99%can be used to predict CVA and the response to anti-asthma treatment.
chronic coughcough variant asthmabronchial diastolic response testlung functionpredictive value