Study designs of evaluations included in the review
Randomised controlled trials (RCTs) were eligible for inclusion. Crossover and parallel group double-blind RCTs were included.
Specific interventions included in the review
Studies that directly compared LABAs plus ICS with either placebo or SABAs plus ICS were eligible for inclusion. Studies of LABAs as monotherapy were excluded. The included studies compared LABAs ( 4.5 to 24 microg formoterol, or 25 to 100 microg salmeterol) with placebo. Some of these studies included a proportion of patients on concomitant ICS (52 to 100%, where stated). The included studies also compared LABAs plus ICS combinations (budesonide/formoterol or salmeterol plus beclomethasone) with ICS alone (budesonide or beclomethasone). In some studies the LABA was added to regular ICS maintenance treatment. The studies lasted from 6 weeks to 12 months.
Participants included in the review
Studies of children with asthma were eligible for inclusion, while those that included both children and adults were excluded. The children in the included studies were aged from 4 to 17 years and had mild to severe asthma.
Outcomes assessed in the review
Studies that reported asthma exacerbation rates or hospitalisation rates for asthma were eligible for inclusion. The studies used different definitions for asthma exacerbation: some defined exacerbation as a deterioration in asthma requiring a change in medication, while other studies provided no definition.
How were decisions on the relevance of primary studies made?
The author did not state how the papers were selected for the review, or how many reviewers performed the selection.