Table 2.

Definitions of objective voluntary cough airflow measures with reference to illustrative cough waveform depicted in Fig. 1

Figure reference	Objective cough measure	Description
Inspiratory phase
A	Inspiratory phase duration (s)	Time from onset of inspiration at 0 L/s to the beginning of glottic closure [1–3] or the start of the expiration onset if there is no appreciable compression phase [3]
B	Inspiratory peak flow rate (L/s)	Peak inspiratory flow during the inspiratory phase [1–3]
Compression phase
C	Compression phase duration (s)	Time to glottic opening measured from the end of the inspiratory phase to the beginning of the expiratory phase [1–4]
Expiratory phase
D	Peak expiratory flow rate (L/s)	Peak expiratory airflow during the expiratory phase of the cough [1–4]
E	Cough expired volume (%)	Percent of total expired volume of air expired during a cough epoch [4]
	Expiratory rise time (s)	Time from the beginning of the expiratory phase to the peak of the expiratory flow [1–3]
	Cough volume acceleration (L/s/s)	A ratio measure derived by dividing expiratory peak flow by expiratory rise time. Proposed to be a measure of cough effectiveness [1–4]

Specific references of published studies utilizing each measure are also provided