Durham 2006.

Methods	Randomised DBPC trial
Participants	Adults 141 active (84 m) 136 placebo (89 m)
Interventions	18 weeks No updosing phase Sublingual tablets 75,000 SQ‐T 15 mcg Phl p 5
Outcomes	Rhinoconjunctivitis symptom score Medication score Post‐treatment specific IgE levels Post‐treatment specific IgG Number of well days
Notes	Jadad scale 5/5
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Low risk	The allocation sequence was generated by the sponsoring company and blinded for the investigators (computer‐generated schedule)
Allocation concealment?	Low risk	Central allocation
Blinding? All outcomes	Low risk	Investigators and participants were blinded to treatment assignment for the duration of the study. Tablet similar in taste, smell and appearance.
Incomplete outcome data addressed? All outcomes	Low risk	Outcome data were completed for each main outcome. 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