Study designs of evaluations included in the review
Only randomised controlled trials (RCTs) that were placebo-controlled and had a minimum follow-up of 24 months were eligible for inclusion. The duration of follow-up in the included studies ranged from 24 to 54 months.
Specific interventions included in the review
Placebo-controlled trials of inhaled corticosteroids were eligible for inclusion. The included studies were of budesonide (400 to 800 microg twice daily), beclomethasone (750 to 1,000 microg twice daily), triamcinolone (600 microg twice daily) and fluticasone (500 microg twice daily). In all studies the comparator drug was placebo. No study permitted the use of both oral and inhaled corticosteroids.
Participants included in the review
Studies of patients with COPD, but not asthma, were eligible for the review. In the included studies, the proportion of male participants ranged from 60.4 to 100%, the mean age ranged from 52.4 to 66.6 years, and the proportion of active smokers ranged from 39 to 100%. The inclusion criteria for FEV1 at entry to the primary studies varied; details were reported. Most of the included studies excluded patients with a bronchodilator response to inhaled corticosteroids.
Outcomes assessed in the review
Studies that reported the decline in FEV1 were eligible for inclusion. The results of other outcomes reported in the primary studies were not reported in the review.
How were decisions on the relevance of primary studies made?
The authors did not state how the papers were selected for the review, or how many reviewers performed the selection.