Tan 1998.

Methods	Setting: Singapore, hospital outpatient clinic Length of intervention period: 1 month Randomisation: yes, method not described Allocation concealment: unclear Design: parallel (with crossover in one arm) Masking: double blind Excluded: not stated Withdrawals: stated (none) Baseline characteristics: comparable Jadad score=3
Participants	30 adults: 20M 10F Age range: 16‐65 years Inclusion criteria: Diagnosis of asthma for at least 1 year (ATS criteria) Nocturnal wakening by wheeze or cough more than once per week in preceding month 20% or greater fall in FEV1 or PEFR from evening to morning on 2 consecutive days before study 15 % or greater Improvement in FEV1 after inhaled beta2 agonist Histamine BHR (PC20FEV1) 8mg/ml or less Exclusion criteria: History of smoking Respiratory tract infection in last 6 weeks
Interventions	BUD: 1600 mcg/d Placebo Delivery device: MDI with built in extension piece (Pulmicort Misthaler)
Outcomes	4 pm, 10 pm, 4 am FEV1 4 pm, 10 pm, 4 am Thoracic Gas Volume 4 pm histamine BHR (PD20FEV1) 4 am histamine BHR (PD20FEV1) 4pm, 10pm, 4 am specific airway conductance (SGaw) Serum neutrophil chemotactic activity Number of night‐time wakenings per week due to asthma
Notes	No reply from author to clarify details of randomisation method. Patients were randomised to either a) 8 weeks of treatment with inhaled BUD or b) 4 weeks of treatment with placebo followed by 4 weeks of treatment with inhaled BUD. In this analysis results from the first 4 weeks only have been considered. This study was specifically concerned with assessing the effects of each intervention on diurnal variability of the outcomes assessed. However in this analysis only the 4pm measurements have been considered.
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear