Robertson 1986.

Methods	Design: cross‐over, 2 weeks washout Randomisation: yes, method not stated (correspondence from Professor Burge ‐ 15 October 2002: double‐blind, allocation concealment used) Blinding: double‐blind, double‐dummy Withdrawals: stated
Participants	Setting: single‐centre study, hospital outpatient clinic Number eligible: 83 Number enrolled: 83 Number in treatment group: 83 (cross‐over) Number in control group: 83 (cross‐over) Number of withdrawals (treatment/control): not stated Number completing trial (treatment/control): not stated Age range: mean 61 years (SD 10) Sex: 66 M, 17 F Ethnicity: no stated COPD diagnosis: FEV1 < 70% predicted Severity of COPD: mean FEV1 44% predicted Inclusion criteria: COPD of at least 5 years duration, chronic bronchitis on MRC questionnaire, 92% were current or ex‐smokers Exclusion criteria: asthma, steroid therapy in previous 6 months Baseline characteristics of treatment/control groups: comparable (cross‐over)
Interventions	BDP 500 µg, 3 times a day (1500 µg/day) Placebo 3 times a day Metered‐dose inhaler 2 weeks each treatment period (cross‐over)
Outcomes	FEV1 in treatment period compared to baseline or placebo FVC in treatment period compared to baseline or placebo PEFR in treatment period compared to baseline or placebo
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Correspondence from Professor Burge ‐ double‐blind, allocation concealment used Comment: probably done
Allocation concealment (selection bias)	Low risk	Correspondence from Professor Burge ‐ double‐blind, allocation concealment used
Blinding (performance bias and detection bias) All outcomes	Low risk	Correspondence from Professor Burge ‐ double‐blind, allocation concealment used
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants completed the study
Selective reporting (reporting bias)	Low risk	Outcomes all reported