The predicting value of small airway diseases for asthma in patients with chronic cough

Objective The aim of this study is to investigate the correlation between small airway disease and airway hyper-responsiveness,and explore the predicting value of small airway diseases for asthma.Methods Pulmonary function tests and bronchial provocation tests were performed in 249 patients with chronic cough from Sep. 2004 to Sep. 2006.The incidence of small airway disease and airway hyper-responsiveness were observed.Results There were 91 patients with small airway disease,and 103 patients with positive tests for bronchial provocation in total 249 chronic cough patients.The incidence of positive tests for bronchial provocation in 91 patients(73.63%)with small airway disease was significantly higher than that in 158 patients(22.78%)without it,P0.01.Also,there was a significant difference in the incidence of positive tests for bronchial provocation in patients with small airway diseases between less than 40 years old and no less than 40,90.0% vs 65.57%,P0.05.Conclusion The small airway disease is an effective predicting factor for asthma,especially to those young patients with chronic cough.