Davies 2012.

Study characteristics
Methods	RCT. Parallel design. Location: single centre in UK. Duration: median length of stay for controls was 14 days, median length of stay for HFCWO group was 13 days.
Participants	36 participants with CF admitted to hospital with an acute infective pulmonary exacerbation. Mean (SD) age: HFCWO group 25.8 (7.3) years; control group 29.8 (1.7) years. Sex: 23 (64%) males.
Interventions	Intervention: HFCWO (device was the Vest®, Hill Rom Model 205), participants paused to huff and cough as necessary. Control: usual airway clearance techniques (including ACBT, AD, PEP, manual techniques or oscillating PEP), further details not given. Treatment given 4x daily ‐ 2x supervised by a physiotherapist and 2x carried out independently.
Outcomes	FEV1, FVC, length of hospital stay and sputum weight. Additional reference to this study also considered FEF25-75.
Notes	Abstracts only and entry on clinicaltrials.gov (NCT01057524) available ‐ no full paper. Further breakdown of data has been requested for inclusion in meta‐analysis.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not discussed.
Allocation concealment (selection bias)	Unclear risk	Not discussed.
Blinding (performance bias and detection bias) All outcomes	High risk	Not blinded. Difficult to blind participants to a device trial, but assessors not blinded either and no reasons given for this.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No drop outs mentioned or missing data discussed.
Selective reporting (reporting bias)	Unclear risk	All parameters stated as recorded were discussed over the 2 abstracts, but no full paper.
Other bias	Unclear risk	Not discussed but there is a possibility of involvement of the manufacturers in provision of the Vest® devices for the 36 participants.