| Methods |
Double blind randomised controlled crossover trial. |
| Participants |
54 chronic asthmatic children 10 to 17 years of age who resided at the asthma centre. Only patients with airways obstruction demonstrated by spirometric and or plethysmographic pulmonary function testing were included, all required around‐the‐clock therapy with theophylline to prevent relapse of asthma. Approximately 60% required alternate‐day corticosteroid therapy and half of the patients were receiving cromolyn sodium. |
| Interventions |
All challenges were performed on days when corticosteroids were not administered. Bronchodilators were not administered for 6 hours but cromolyn sodium therapy was not suspended. All patients underwent double blind challenges to placebo, 600mg acetylsalicylic acid and 25mg tartrazine. on separate days. The study was discontinued ten months later when 32 of the original patients had completed the study. |
| Outcomes |
FEV1, FEF25‐75, blood pressure. 15% fall in FEV1 defined a positive test result. |
| Notes |
No data was presented for the tartrazine arm as the authors did not find and significant differences and therefore did not report results. No reply to correspondence received from author to date. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
Information not available |
