Table 4.

Flowchart for Screening Chronic Unexplained, Refractory/Intractable, or Idiopathic Cough in Included Studies

Study	Investigations								Exclusions of Diseases
	No Smoking	ACEI	Chest Imaging	Sinus Imaging	BPC	Induced Sputum	Bronchoscopy	Esophageal pH
Khalid et al,24 2014	Yes	No	Yes	Yes	Yes	Unclear	Yes	Yes	NA
Ryan et al,34 2012	Yes	Yes	No	No	No	Yes	No	No	COPD, asthma, respiratory infection
Shaheen et al,36a 2011	Yes	Yes	Yes	No	No	No	No	No	Aerodigestive malignancy or Barrett’s oesophagus, upper respiratory infection
Yousaf et al,35 2010	Yes	No	Yes	No	Yes	Yes	No	No	Asthma, EB, bronchiectasis, chronic lung disease, GERD, UACS
Rytila et al,27 2008	Yes	No	Yes	Yes	Yes	No	No	No	COPD, asthma, upper respiratory infection, UACS, GERD
Morice et al,25 2007	Yesb	Yesb	Yesb	Yesb	Yesb	No	Yesb	Yesb	NA
Ribeiro et al,29 2007	No	No	Yes	Yes	No	No	No	No	GERD, respiratory infection, asthma, COPD, rhinosinusitis, UACS
Vertigan et al,23 2006	No	Yes	Yes	Unclear	Unclear	Yes	Unclear	Unclear	Upper respiratory tract infection, allergy, UACS, asthma, GERD, EB, lung pathology, COPD, neurologic voice disorder
Jeyakumar et al,22 2006	Yes	Yes	Yes	No	No	No	Yes	No	Asthma
Pizzichini et al,39 1999	Yes	Yes	Yes	Yes	Yes	No	No	No	Respiratory tract infection, chronic bronchitis, sinusitis, asthma
Holmes et al,26 1992	Yes	Yes	Yes	Yes	Yes	No	Yes	No	Asthma, GERD

BPC = bronchial provocation challenge; EB = eosinophilic bronchitis; UACS = upper airway cough syndrome. See Table 1 and 2 legends for expansion of other abbreviations.

^aInhaled or oral corticosteroids were prescribed although nonasthmatic eosinophilic bronchitis/asthma were not indicated in the study.

^bBased on the previously published probability-based treatment algorithm.²⁸