Valovirta 2006.

Methods	Randomised DBPC trial
Participants	Children 35 active Dose group one 33 patients (19 m); losses to f/u 1 Dose group 2: 32 patients (13 m); losses to f/u 7 33 placebo (18 m); losses to f/u 6
Interventions	18 months SLIT Group 1: accumulated weekly dose 3.6 mcg Bet v 1/ Aln g 1/ Cor a 1 Group 2: accumulated weekly dose 30 mcg of Bet v 1/ Aln g 1/ Cor a 1 5 weeks updosing schedule
Outcomes	Symptom score Medication score
Notes	Jadad scale 5/5 2 treatment groups Mixed tree pollen
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Patients were randomised but how this was done was not stated
Allocation concealment?	Low risk	Central allocation
Blinding? All outcomes	Low risk	The study was conducted under double‐blind conditions. There was no difference in colour and viscosity between the study drug and placebo. All blinding procedures were performed by the Quality Assurance Department at ALK‐Abello A/S.
Incomplete outcome data addressed? All outcomes	Low risk	Outcome data for each main outcome completed, including attrition and exclusions from the analysis. Attrition and exclusions were reported; the numbers in each intervention group and reasons for attrition/exclusions were reported.
Free of selective reporting?	Low risk	The specified outcomes in the methodology were reported in the results section
Free of other bias?	Low risk	No other sources of bias were detected or suspected