Establish FeNO cut-off value for predicting Budesonide-formoterol response in chronic cough suggestive of CVA patients. - EFFICIENCY

This is a multicenter, prospective, single-arm, interventional clinical study to predict the response to budesonide-formoterol treatment in patients with chronic dry or nocturnal cough by determining a cut off value of FeNO. In this study, the response to ICS/LABA treatment is defined as reduction in cough VAS score from baseline of ≥30 mm after 8 weeks of ICS/LABA treatment. Subjects will be treated with Symbicort® 160/4.5 mcg, 1 puff, BID for 8 weeks with 4 study visits: Visit 1 (Day 0), Visit 2 (week 4) and Visit 3, end of study (week 8) and Visit 4, 4 weeks after treatment discontinuation, (week 12). Baseline data will be collected at Day-5 to Day0. This study will be conducted at around 40 study sites in China. Approximately 1000 patients (age ≥18 years old) with dry cough or nocturnal cough symptoms for at least 8 weeks and no other obvious cause for their cough will be enrolled into this study.