Study design

Design:

randomised controlled trial (RCT).

Allocation:

{concealed}†.*

Blinding:

{unblinded}†.*

Study question

Setting:

8 clinical centres in Canada and the USA.

Patients:

1041 patients 5–12 years of age {mean age 9 y, 60% boys}‡ who had chronic mild to moderate asthma and airway responsiveness to methacholine. Exclusion criteria included {other pulmonary disease or ventilatory defect, severe chronic sinusitis or nasal polyposis, use of >4 sprays/day of nasal steroids (except beclometasone), and treatment for gastro-oesophageal reflux}.†

Intervention:

after a mean 4.3 years of treatment, patients stopped continuous treatment with budesonide Turbuhaler, 200 μg twice daily {n = 311}‡; nedocromil, 8 mg twice daily {n = 312]‡; or placebo matching budesonide {n = 208}‡ or nedocromil {n = 210}‡.

Outcomes:

FEV₁ % of predicted post-bronchodilator. Secondary outcomes included FEV₁ % of predicted pre-bronchodilator use, prednisone courses, urgent care visits, and adverse effects (height). {The study had 90% power …