| Study characteristics |
| Methods |
Randomised within each centre by computer‐generated random number sequence in blocks of 6.
Double‐blinded. Parallel study.
Multicentre (15 centres). |
| Participants |
285 participants recruited.
CF diagnosed on clinical features and 2 raised sweat chloride (or sweat sodium) values.
Inclusion criteria: aged 6 ‐ 14 years; clinical stability without hospitalisation for CF‐related problems within 2 months of entry; serum IgG within 2 standard deviations of normal for centre or hypogammaglobulinaemia; reliable performance of lung function tests for at least 6 months prior to enrolling in trial; FEV1 > 60% predicted and FEV1/FVC ratio > 60% predicted.
Exclusion criteria included previous treatment with oral, inhaled or nasal corticosteroids for more than 2 weeks within 6 months of entry or any form of corticosteroids in previous month, evidence of liver disease, treatment with non‐steroidal anti‐inflammatory treatment. |
| Interventions |
Prednisone 2 mg/kg or prednisone 1 mg/kg or placebo on alternate days (maximum dose 60 mg). Participants who missed 30% or more of total prescribed study medication were labelled as non‐compliant but still included in analysis. |
| Outcomes |
Primary outcomes were lung function (FEV1, FVC), serum IgG concentrations, growth and hospitalisation rates.
Lung function was assessed at baseline and at 6, 12, 18, 24, 30, 36, 42 and 48 months.
Serum IgG was measured at baseline and at 3, 6, 12, 24, 36, 42 and 48 months.
Height and weight were measured by techniques standardised across all participating centres. Height scores were calculated on the basis of age‐stratified normal populations.
Adverse events were monitored every 3 months with emphasis on raised blood glucose concentration, cataracts, raised liver enzymes and respiratory infection with unusual organisms (opportunistic infection).
Growth was assessed in a 10‐year follow‐up study. |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Randomised within each centre by computer‐generated random number sequence in blocks of 6. |
| Allocation concealment (selection bias) |
Unclear risk |
Unclear. |
| Blinding (performance bias and detection bias)
All outcomes |
Unclear risk |
Described as double‐blind and same number of tablets given for each regimen, but true blinding might not have been possible since at the doses used, it would have been obvious from treatment effects which participants were in the treatment group. |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
Participants who missed 30% or more of total prescribed study medication were labelled as non‐compliant but still included in analysis. |
