Lyons 1992.

Study characteristics
Methods	RCT. Cross‐over design (4 treatment arms, no washout). Location: single centre in UK. Duration: 4 successive days (1 day per treatment arm).
Participants	12 participants (5 males, 7 females). Mean age 21 years (range 16 ‐ 28).
Interventions	PD&P versus Flutter alone versus Flutter with PD&P versus sham flutter with PD&P. 3x a day for each treatment.
Outcomes	Used sputum volume and peak flows only. Measured after 24‐hour period for 4 days.
Notes
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)	Unclear risk	Not discussed.
Other bias	Unclear risk	Abstract only.