Wempe 1992a.

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	8 adults: 5M 3F Age range: 18 ‐40 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 x daily (800mcg/d) Placebo: 2 pfs 2 x daily Delivery device: Turbuhaler DPI Bambuterol: 20mg tablet 1xdaily Each group received appropriate additional 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	No reply from author to clarify details of randomisation method. Patient group with daily PEFR variability > 15%
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear