Wempe 1992b.

Methods	Setting: The Netherlands, hospital outpatient clinic Randomisation: yes, method not stated Allocation concealment: unclear Design: crossover, no washout Intervention period: 4 weeks Masking: double blind Excluded: not stated Withdrawals: stated (none) Baseline characteristics: comparable Jadad score=3
Participants	9 adults: 6M 3F Age range: 18 ‐39 years Inclusion criteria: Adult patients with asthma Positive skin prick test and elevated specific IgE to house dust mite FEV1 (% predicted) > 60 Histamine BHR (PC20 FEV1) < 8 mg/ml Diurnal PEFR variability < 15% Exclusion criteria: Asthma exacerbation within last 2 months
Interventions	BUD: 200mcg 2 pfs 2 xdaily (800mcg/d) Placebo: 2 pfs 2xdaily Delivery device: Turbuhaler DPI Bambuterol: 20mg tablet 1xdaily Each group received appropriate addtional placebo tablet or inhaler to maintain blinding
Outcomes	24 hour mean FEV1 (% predicted) Diurnal change in FEV1 (% predicted) Histamine BHR (PC20 FEV1) Diurnal change in histamine BHR (PC20 FEV1) Daytime cough, breathlessness and wheeze scores Night‐time cough, breathlessness and wheeze scores
Notes	Patient group with daily PEFR variability < 15%
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear