Grzincich 2008

Methods	RCT. Parallel design Duration: first 3 days of hospitalisation for an exacerbation.HFCWO or PEP
Participants	23 participants (12 females). Mean age 25 years.
Interventions	HFCWO at setting of 20 Hz for 30 minutes compared with 30 minutes of PEP for the first 3 days of treatment.
Outcomes	FEV₁, FVC and FEF 25‐75 were assessed pre and 30 minutes post intervention. Sputum volume was collected after each intervention.
Notes	Abstract only, full paper not published as yet. No identification how many participants were randomised to each treatment. There were no statistical data given but reference made to state P < 0.05 was significant but this was not attributed to any result.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Described as randomised, 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; data provided but significance not statistically represented.
Selective reporting (reporting bias)	Unclear risk	Not possible to compare original trial protocol with final paper. Additionally a P value was suggested in the abstract but not attributed to any specific outcome measured.
Other bias	Unclear risk	Abstract only. Details of methodology are scarce