van der Giessen 2007b

Methods	Randomised, blinded, cross‐over placebo‐controlled trial with 2‐week interventions, no washout. Measurements were taken at 0, 14, 21 and 28 days. Generation of allocation schedule was clear but concealment of treatment allocation was unclear. ITT analysis was used.
Participants	25 stable (no IV treatment 1 month previously) children randomised: mean age 13 years (range 6 years ‐ 19 years); mean FEV1 75% predicted. One child dropped out while inhaling dornase alfa in the evening.
Interventions	Morning (on waking) compared to evening (before bedtime). ACT performed for 30 minutes post morning inhalation. ACT not described. Maintenance dornase alfa.
Outcomes	FEV1, FVC, symptom scores (VAS for cough and CSS day & night, sleep quality, sputum viscosity and amount). FEF25, Rint, adherence (vials), adverse events (overnight oximetry and cough per hour recordings).
Notes	PEDro 9/10 (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; Intention‐to‐treat analysis: Yes; 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	Low risk	1 drop out due to exacerbation, ITT applied.
Selective reporting (reporting bias)	Low risk	Adherence data were only provided for the whole study cohort and not by study arm.

ACT: airway clearance technique AD: autogenic drainage CFQ: cystic fibrosis questionnaire CSS: cough symptom score SD: standard deviation FEF_25‐75: mid‐expiratory flow FEV₁: forced expiratory volume at one second FVC: forced vital capacity ITT: intention‐to‐treat IV: intravenous FEF₂₅: forced expiratory flow at 25% of FVC PD: postural drainage PEP: positive expiratory pressure QOL: quality of life QWB: quality of well‐being scale Rint: resistance measured by the interrupter technique VAS: visual analogue scales VO₂max: measure of the peak volume of oxygen (VO₂) you can consume and use in a minute