Table E1.

Definition of clinical features

Clinical feature	Definition
Nonproductive cough	Cough was nonproductive or minimally so
Daily cough alone	Cough mainly occurs at daytime and before bedtime
Nocturnal cough alone	Cough mainly occurs after falling asleep
Total nocturnal cough	Cough occurs at night, with or without daily cough
Trigger-eating	Cough when eating
Trigger-after meals	Cough after meals
Reflux-related symptoms	Experienced 1 or more symptoms of acid regurgitation, heartburn, and belching
Combined reux symptoms	Presence of all of the following symptoms: regurgitation, heartburn, and belching
Rhinitis/sinusitis-related symptoms	Experienced 1 or more symptoms of sneezing, nasal itching, runny nose, and nasal congestion
History of gastrointestinal disorders	Previously diagnosed as chronic gastritis, stomach ulcer, or gastroesophageal reflux disease, etc
History of rhinitis	Previously diagnosed as allergic rhinitis or nonallergic rhinitis
History of sinusitis	Previously diagnosed as acute sinusitis or chronic sinusitis