| Methods |
Randomisation: stratified by baseline forced expiratory volume in 1 second (FEV1) (no details of allocation concealment)
Blinding: single blind
Number excluded: no details
Withdrawals: not stated
Baseline characteristics: FEV1 comparable in each group |
| Participants |
Location: Wurzburg, Germany
Number and age of participants: 52 asthmatic patients (age not stated)
Asthma definition and severity: reversible airways obstruction. 9 included patients used systemic corticosteroids
Inclusion criteria: 20% rise in FEV1 following fenoterol, or 20% spontaneous change in FEV1 recordings or documented breathing difficulty with deterioration in lung function |
| Interventions |
Vaccination types:
1. Split virus vaccine A/90/70, A/1/77, B/8/73 (injection in deltoid)
2. Subunit vaccine A/92/77, A/1/77, B/8/73 (injection in deltoid)
Placebo: saline injection (in deltoid) |
| Outcomes |
Lung function measurements in clinic (2 weeks before and after treatment). Home measurement of peak flow (best of 3, twice daily) and symptoms recorded by patients (including breathing difficulty) |
| Notes |
No lung function measurements documented, only "no significant change in lung function following either vaccination or placebo" (even in the patients on systemic corticosteroids) |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Stratified randomisation (communication from the authors) |
| Allocation concealment (selection bias) |
Low risk |
The physician always had to pick the next available vial and was not allowed to change sequence |
| Blinding of participants and personnel (performance bias)
All outcomes |
Unclear risk |
No details of any differences in appearance between placebo and active injections |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
The code was opened at the end |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
No details |
