Simons 1997.
Methods | Setting: multicentre study Canada, hospital outpatient clinics Length of intervention period: 12 months Randomisation: yes, computer generated sequence Allocation concealment: yes (off site body generated list, with coded schedules) Design: parallel group Masking: double blind Excluded: stated Withdrawals: stated Baseline characteristics: comparable Jadad score: 4 | |
Participants | 241 children: 140M 101F Age range: 6 to 14 years Inclusion criteria: Children with clinically stable asthma (not otherwise defined) No more than 1 month of treatment with corticosteroids for asthma in past No inhaled or oral corticosteroid treatment within last 3 months FEV1 > 70 (% predicted) 10% or greater increase in FEV1 after inhaled beta2 agonist Methacholine BHR (PC20 FEV1 < 8mg/ml) Exclusion criteria: Emergency dept attendance or hospital admission due to asthma exacerbation within last 3 months History of life‐threatening asthma History of adverse reaction to study medications | |
Interventions | BDP: 200 mcg 2x daily (400 mcg/d) Placebo: 2xdaily Delivery device: Diskhaler DPI |
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Outcomes | Methacholine BHR (PC20 FEV1) FEV1 (% predicted) FEV1 FVC FEF 25, FEF 50, FEF 75, FEF25‐75 Morning PEFR Evening PEFR Clinic PEFR Rescue beta2 agonist not required (% of children) Waking at night (% of nights) No school missed because of asthma (% of children) Waking at night (% of nights) Activities affected by asthma (% of days) Height assessment Blood eosinophil count Withdrawal due to asthma exacerbation (number of patients) | |
Notes | Reply from author clarifying method of random order generation and use of allocation concealment. Exacerbation of asthma defined as the presence of symptoms despite study medication and the use of albuterol as rescue medication. If an exacerbation occurred, children were treated with oral prednisolone 1mg/kg for 5 to 7 days. If symptoms still not controlled children were withdrawn. Also withdrawn if : More than 1 course prednisolone required in month or 4 in year or: Hospitalization for asthma required Non‐parametric tests used to compare symptom outcomes Salmeterol treatment arm: results not included | |
Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Allocation concealment? | Low risk | A ‐ Adequate |