Verhoeven 2002.

Methods	Design: parallel group Randomisation: yes, method not stated Blinding: double blind, double dummy Withdrawals: stated
Participants	Setting: single centre study, hospital outpatient clinic Number eligible: not stated Number enrolled: 23 COPD; also studied 6 asymptomatic smokers Number in treatment group: 10 Number in control group: 13 Number of withdrawals (treatment/control): 0/0 Number completing trial (treatment/control): 10/13 Age range: 42 to 67 yr Sex: 19M, 4F Ethnicity: not stated COPD diagnosis: chronic productive cough, FEV1 <=70% predicted Severity of COPD: mean FEV1 66% predicted FP, mean FEV1 61% predicted placebo Inclusion criteria: non‐specific BHR (PC20 histamine <=8 mg/ml), current smoker, FEV1 reversibility <10% after terbutaline, normal serological examination (Phadiatop test), negative skin prick tests for aeroallergens Exclusion criteria: asthma, respiratory tract infection in previous 4 weeks, serious or unstable concomitant disease Baseline characteristics of treatment/control groups: comparable
Interventions	FP 500 µg, 2 times a day (1,000 µg/d) placebo Diskhaler 6 months
Outcomes	BHR methacholine Bronchial biopsies Lung function tests Serum cortisol
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "randomly allocated"
Allocation concealment (selection bias)	Unclear risk	Information not available
Blinding (performance bias and detection bias) All outcomes	Low risk	Quote: "double blind"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Low risk	All outcomes reported