Robinson 2005.

Methods	Randomised double‐blind, placebo‐controlled trial. Parallel design. Duration: 1 year. Participants evaluated at 3 months and 1 year.
Participants	25 children randomised. Age: range 6 ‐ 18 years old. Disease status: normal or mildly reduced lung function (FVC ≥ 85%, FEV1 > ˜70%). There were 4 withdrawals, all were for non‐trial drug‐related reasons.
Interventions	Treatment: rhDNase 2.5 mg once daily. Control: normal saline aerosol once daily.
Outcomes	Included in this review: FEV1(% predicted), FVC (% predicted). Not included in this review: FEF25‐75, high resolution CT scores, composite score including high resolution CT and PFT data.
Notes	Measurements were taken at 3 and 12 months.
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	Double blinded (investigators, participants blinded to treatments until trial end).
Incomplete outcome data (attrition bias) All outcomes	Low risk	ITT analysis used. 4 withdrawals, all were for non‐trial drug‐related reasons.
Selective reporting (reporting bias)	Low risk	None identified.
Other bias	Low risk	None identified.