Bourbeau 1998.

Methods	Design: double blind, randomised, parallel group trial Duration: 6 months (originally intended to be 12 months) Location: single centre in Canada
Participants	Population: 79 people were randomised to budesonide (39) and placebo (40) Baseline characteristics Age (mean years): bud 66, pbo 66 Male %: bud 84.6, pbo 72.5 % FEV1 predicted: bud 36, pbo 37 Pack‐years (mean): bud 52, pbo 50 Inclusion criteria: Age 40 years old or older; smokers or ex‐smokers; absence of an exacerbation in respiratory symptoms during the two months prior to the study; pre‐bronchodilator FEV1 less than 65% of predicted12 and FEV1/forced vital capacity (FVC) less than 0.65; post‐bronchodilator FEV1 less than 80%; regular treatment with at least one bronchodilator Exclusion criteria: history of allergic asthma during childhood or as an adult; inhaled corticosteroids in the previous month or oral corticosteroids in the previous two months; any other active lung disease; diabetes, active peptic ulcer disease, uncontrolled high blood pressure, or congestive heart failure; disease other than COPD that might interfere with quality of life
Interventions	1. Budesonide 800 bid (ICS) 2. Placebo (PBO) Inhaler device: Turbohaler Allowed co‐medications: All medication for the well‐being of the patients was permitted except inhaled corticosteroids other than budesonide. In case of treatment failure, rescue medication with beta‐2 agonists or systemic steroids was available
Outcomes	Pre‐ and post‐bronchodilator FEV1 and FVC, pre‐bronchodilator six minute walking test, dyspnoea with exercise, quality of life questionnaires, morning and evening PEFR, symptom scores and adverse events
Notes	Funding: Astra Pharma Inc Identifier(s): unknown
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Central computer‐generated list of random numbers
Allocation concealment (selection bias)	Low risk	Identification of individual treatment assignments was only possible in case of emergency by breaking the sealed envelope kept by the investigator. The envelopes had to be kept with the case record forms and be returned unbroken at the end of the study.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	To assure that outcomes were measured similarly in the treatment groups, the patients and the investigators were blinded to the study treatment
Blinding of outcome assessment (detection bias) All outcomes	Low risk	To assure that outcomes were measured similarly in the treatment groups, the patients and the investigators were blinded to the study treatment
Incomplete outcome data (attrition bias) All outcomes	High risk	Uneven dropout. Much higher in placebo group (25% versus 7.7% in the ICS group)
Selective reporting (reporting bias)	High risk	Key outcomes missing (mortality, adverse events). No reply from author.