Osman 2010.

Study characteristics
Methods	RCT. Cross‐over design (no washout). Location: single centre in UK. Duration: 4 days.
Participants	30 participants recruited (22 males). Mean age: 29.7 years. Mean FEV1: 37.7 %
Interventions	HFCWO versus "usual" ACT (83% of "usual" therapy was described as ACBT, AD, flutter or PEP). Participants received either HFCWO on days 1 and 3 and the "usual" ACT on days 2 and 4 or vice versa. Sessions were 2x daily for 30 min.
Outcomes	Wet weight of expectorated sputum, respiratory function, oxygen saturation monitoring, perceived efficacy and preference were measured.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Allocation to HFCWO or usual ACT on Day 1 was determined using a computer‐generated randomisation table.
Allocation concealment (selection bias)	Unclear risk	Not discussed.
Blinding (performance bias and detection bias) All outcomes	Low risk	Not possible to blind participants or clinicians, but paper states: "An independent observer, blind to the daily method of airway clearance used, performed the spirometry, weighed the sputum samples and collected the 10 cm VAS throughout the study."
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 sputum samples were removed from total of 116 collected as they were incomplete.
Selective reporting (reporting bias)	Unclear risk	Powered to detect a 4 g difference in expectorated sputum.
Other bias	High risk	Supported by Robery Luff Foundation and Hill‐Rom Ltd. Levels of oxygen saturation measured were higher at baseline in the HFCWO group which potentially could influence outcome as groups were not balanced at the beginning of the intervention.