2.3 Survey development
Each of the patients underwent the following procedures for the
investigation of the cause of cough: 1) recording of medical history
including symptoms and history of ear, nose, throat, respiratory tract,
and digestive tract problems; 2) detailed physical examination with the
targeted evaluation of throat congestion, follicular hyperplasia, and
retropharyngeal postnasal drip; and 3) chest X-ray examination,
bronchodilator test, methacholine-challenge test, CT imaging of the
sinuses, or endoscopy in patients with suspicious symptoms or signs.