Fig. 1
From: Clinical and pulmonary function changes in cough variant asthma with small airway disease
Patients screen and follow up. 250 subjects were screened and 173 subjects were excluded for wrong phone number, no will to attend the trial or age limitation. 77 initially diagnosed CVA patients were enrolled. Participants were divided into two groups: CVA with lower FEF50%, CVA with normal FEF50%. Twenty participants were dropped out during follow up. A total of 57 patients complete the observation over a year