TABLE 2.

Summary of interventions investigated in the studies included in this review

Secretion clearance techniques	Breath stacking/air stacking, lung volume recruitment	34 (45)
	Manual assisted cough	30 (40)
	Mechanical insufflation–exsufflation	25 (33)
	High-frequency chest wall compression/high-frequency chest wall oscillation	8 (11)
	Glossopharyngeal breathing	5 (7)
	Manual insufflation	5 (7)
	Positioning/postural drainage	5 (7)
	Intermittent positive pressure breathing	4 (5)
	External glottic device	3 (4)
	Intrapulmonary percussive ventilation	3 (4)
	Exsufflation only	2 (3)
	Functional electrical stimulation	2 (3)
	Inspiratory muscle training	1 (1)
	Positive expiratory pressure/bubble positive expiratory pressure	1 (1)
	Other#	7 (9)
Individual administering intervention	Clinician (physician, physiotherapist, respiratory therapist, nurse, technician)	25 (33)
	Family member/carer	15 (20)
	Patient	11 (15)
	Not reported	33 (44)

Data are presented as n (%) out of a total of 75 studies. Proportions do not always sum to 100% as multiple interventions were used in some studies and multiple individuals administered the intervention. ^#: includes incentive spirometry, proprioceptive neuromuscular facilitation, continuous positive airways pressure, noninvasive ventilation, expiratory flow accelerator, forced expiration technique and breathing exercises.