ABSTRACT
Objective To investigate the etiological diagnosis utilization value of bronchial provocation tes(tBPT) in patients with chronic cough variant asthma(CVA) .Methods The bronchial provocation test was performed to assess the bronchial responsiveness by inhaling methacholine in 1155 patients with chronic cough.RESULTS There was no significant difference of pulmonary function in vary age groups.The positive rate of bronchial provocation test was 50.6%(584/1155,285 males,299 females,In those patients with positive result,547 patients were diagnosed as CVA,25 patients as post-infection cough,and 12 patients as chronic bronchitis.Spe-cificity of BPT was 93.9%.The population under 30 years had the highest CVA diagnostic rate of 68.8%and those over 60 years had the lowest diagnostic rate of 23.5%.These two groups had significant difference when compared to the other age groups respectively.Conclusions CVA is the main cause of chronic cough.The BPT is a simple and effective method in the diagnosis of CVA at early stage.