Study designs of evaluations included in the review
Randomised, double-blind, placebo-controlled trials were included.
Specific interventions included in the review
Inhaled ipratropium bromide and placebo in conjunction with inhaled beta2-agonists (fenoterol or salbutamol).
Participants included in the review
Children under 18 years who had an acute unprovoked asthma attack (by reasonable definition) were included.
Outcomes assessed in the review
Any of the following clinical or physiological outcomes were measured: change in vital signs, length of admission, peak expiratory flow rate (PEFR), clinical rating scores of asthma severity, number of admissions to hospital and the forced expiratory volume in 1 second (FEV1)
How were decisions on the relevance of primary studies made?
Agreement regarding the relevance of studies was determined by calculating weighted kappa values with quadratic weights for the first 218 titles. There was 92% agreement giving a weighted kappa of 0.67.