Robinson 1997.

Methods	Randomised controlled trial. Design: cross‐over with 4 arms (no information on any washout period). Duration: each intervention given on 1 study day. Location: Australia.
Participants	Total participants: n = 10, 7 males and 3 females. Age mean (SD) (range): 22.1 (3.8) (19 ‐ 28) years. FEV1 % predicted mean (SD) (range): 52.0% (6.7) (31 ‐ 84%). All participants were chronically colonisedPseudomonas aeruginosa. In addition, 5 of the participants had Staphylococcus aureus. Participants in a stable clinical condition and baseline medications were not altered throughout the trial period.
Interventions	Pre‐treated with nebulised salbutamol 5 mg in 2.5 mL saline via an ultrasonic nebuliser. Group 1: HS 3% single dose. Group 2: HS 7% single dose. Group 3: HS 12% single dose. Group 4: Voluntary cough and IS combined as the control. Each participant took part in each arm.
Outcomes	Sputum isotope % clearance at 30 minutes, sputum isotope clearance at 90 minutes, mucociliary clearance.
Notes	No sample size calculation stated.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No detail provided.
Allocation concealment (selection bias)	High risk	There was no random allocation to treatment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants could discern taste for intervention.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not discussed.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No discussion of whether an intention‐to‐treat analysis had been used or of any withdrawals.
Selective reporting (reporting bias)	Low risk	All outcomes stated in the methods were described in the results.
Other bias	High risk	Washout period not clear. No sample size calculation stated. The time course of the effect of the interventions on the outcomes is not clear.