Reflux-cough syndrome: Assessment of temporal association between reflux episodes and cough bursts.

GASTROESOPHAGEAL reflux; COUGH diagnosis; SYMPTOMS; ENDOSCOPY; RESPIRATORY infections; CHEST pain

Background Gastro-esophageal reflux can be the cause of chronic cough. In the assessment of the temporal association between reflux and cough, previous studies have used a two-minute time window, based on studies in patients with heartburn. However, it remains unclear whether the optimal time window duration for the evaluation of reflux-induced cough is two minutes as well. Therefore, we aimed to determine whether a two-minute time window is optimal to diagnose reflux-induced cough. Methods In this multicenter study, 137 patients with chronic cough were evaluated using 24-h pH-impedance-pressure monitoring. Repetitive symptom association analysis was employed using an array of time windows of various duration. For each time window, the symptom association probability ( SAP) and symptom index ( SI) were calculated. Key Results A total of 4377 cough burst episodes and 5074 reflux episodes were detected. The number of patients with a positive SAP increased with increasing window duration until a plateau was reached around a time window duration of 1.5 min. Similarly, the SI increased steeply until a window duration of about 2 min, after which a linear increase was seen. Conclusions and Inferences A two-minute time window seems appropriate for evaluation of the relationship between reflux and chronic cough using 24-h pH-impedance-pressure monitoring. A time window duration of 30 s or 1 min is too short to diagnose patients with reflux-induced cough accurately. [ABSTRACT FROM AUTHOR]