Hansen 1990.

Study characteristics
Methods	RCT. Cross‐over design. Location: single centre in USA. Duration: not defined.
Participants	5 participants. Age and sex of participants not stated.
Interventions	HFCWO versus CPT. 30 sessions of each therapy lasting same duration, but duration of treatment was not defined.
Outcomes	Sputum weight. Primarily looking at the pressure and frequencies generated by the vest and the mucus collection was an aside. Measured before and after duration of intervention (30 days).
Notes	In addition a gentleman not wanting to be included in the study used the Vest® for 12 months and experienced a significant increase in his RFTs and restoration of ventilation to the upper lobes of his chest on scanning.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, but method not discussed.
Allocation concealment (selection bias)	Unclear risk	Not discussed.
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not discussed.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not discussed.
Selective reporting (reporting bias)	High risk	Only reporting of respiratory function was descriptive of the man not included in the study.
Other bias	Unclear risk	None identified.