van Asperen 1992.

Methods	Multicentre randomized placebo‐controlled double‐blind study. Randomisation stratified by two age groups (6 to 18 months and 19 to 36 months) and two symptom groups (cough alone and wheeze with or without cough). High quality score = 2 Grading of quality: Allocation concealment = B Blinding = A Reporting of participants by allocated group = A Follow up = B
Participants	113 infants between 6 and 36 months of age presenting with a history of cough or wheeze for at least 50% of days over 3 or more months or both. Other inclusion criteria: nil mentioned. Exclusion criteria: presence of any serious chronic disease, other specific lung disease, previous long term use of cromoglycate, on theophylline or cromoglycate, or have used steroids for > 5 days in last 3 months. Recruited through outpatients and community advertising
Interventions	4 week run‐in then 16 weeks of 2.5 ml twice daily of either placebo or Ketotifen (0.5 mg) syrup; this was followed by a 4 week wash‐out observation phase.
Outcomes
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Adequate sequence generation?	Unclear risk	Not described
Allocation concealment?	Unclear risk	Not described
Blinding? All outcomes	Low risk
Incomplete outcome data addressed? All outcomes	Low risk
Free of other bias?	Unclear risk	Supported by pharmaceutical company

bd: twice daily; ECG: electrocardiogram; SD: standard deviation; s.e.m: standard error of the mean