Osterman 1997.

Methods	Setting: multicentre study Sweden, hospital outpatient clinic Randomisation: yes, computer‐generated randomisation sequence Allocation concealment: yes (codes held by pharmaceutical company sponsors) Design: parallel Intervention period: 12 months Masking: double blind Excluded: not stated Withdrawals: stated Baseline characteristics: comparable Jadad score=5
Participants	75 subjects: 33M 42F Age range: 18‐68 years Inclusion criteria: Clinical diagnosis of asthma, made not more than 1 year previously Histamine BHR (PD20 FEV1) < 0.66 mg Exclusion criteria: Teatment with anti‐inflammatory drugs within previous 3 months
Interventions	BUD: 200 mcg 1pf 2xdaily (400 mcg/d) Placebo: 1pf 2xdaily Delivery device: Turbuhaler DPI
Outcomes	Change in FEV1 and % predicted FEV1 compared to baseline Histamine BHR (PD20 FEV1) Change in daytime and night‐time beta2 agonist use Change in serum ECP, MPO, ECA and NCA compared to baseline Withdrawal due to asthma exacerbation
Notes	Reply from pharmaceutical company sponsors confirming use of allocation concealment
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Low risk	A ‐ Adequate