Milne 2004

Methods	RCT (pilot study). Cross‐over design (1 day washout between 2 treatment arms). Location; single‐centre in South Africa. Duration: 5 days (2 days per treatment with 1 day washout in between).
Participants	7 participants with CF; mean age 28 years (range 16 ‐ 42 years).
Interventions	Flutter versus ACBT. Group A: flutter, then washout, then ACBT. Group B: ACBT, then washout, then flutter.
Outcomes	Daily 24‐hour sputum samples and lung function tests (FEV₁, FVC, PEF, FEF25, FEF50, FEF75), questionnaire at end of study.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised to either one group or another but generation of sequence not discussed.
Allocation concealment (selection bias)	Unclear risk	Not discussed.
Blinding (performance bias and detection bias) All outcomes	High risk	Additional person was used to perform the lung function tests and is included in the acknowledgements it is not clear if this person was blinded to the treatments.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data sets were complete for all those participants included in the study.
Selective reporting (reporting bias)	Unclear risk	No major side effects were experienced with either technique.
Other bias	Low risk	Possible limitations of the study were discussed and the author suggested various means to improve the findings of the study.