van der Giessen 2007a.

Methods	Randomised, blinded, cross‐over placebo‐controlled trial with 3‐week interventions, no washout. Measurements were taken at 0, 14, 21, 35 and 42 days. Generation of allocation schedule and concealment of treatment allocation were unclear. ITT analysis was not used.
Participants	25 stable (no IV treatment 1 month previously) children randomised: mean age 12 years (range 7 years ‐ 19 years), mean FEV1 88% predicted. One child dropped out while inhaling dornase alfa before airway clearance.
Interventions	Delivery 30 minutes before airway clearance techniques compared to delivery immediately after airway clearance. ACT = PEP mask in 75%, Flutter in 13%, ACBT in 4%, AD in 4% and combination 4%. Maintenance dornase alfa.
Outcomes	FEV1, FVC, symptom scores (VAS for cough and CSS day & night, sputum viscosity and amount). FEF25‐75, FEF25, Rint, adherence (vials), adverse events.
Notes	PEDro 8/10 (eligibility criteria: yes; random allocation: yes; concealed allocation: no; baseline comparability: yes; blind participants: yes; blind therapists: yes; blind assessors: yes; Adequate follow‐up: yes; ITT analysis: no; between‐group comparisons: yes; point estimates and variability: yes).
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Stated as randomised but no method was described.
Allocation concealment (selection bias)	Unclear risk	Method unclear.
Blinding (performance bias and detection bias) All outcomes	Low risk	Placebo used; participants, therapists and assessors blinded.
Incomplete outcome data (attrition bias) All outcomes	High risk	Not analysed as ITT, one drop out due to exacerbation.
Selective reporting (reporting bias)	Low risk	Adherence data were only provided for the whole trial cohort and not by trial arm.