Combivent 1994.
| Methods | RCT: 12 week (three arm) parallel group MDI study. Randomisation: computer generated Blinding: double blind Excluded: not described. Withdrawals: described. Baseline characteristics: comparable Power calculation: not given. Intention to treat analysis. Jadad Score:5 | |
| Participants | Setting: USA, multi‐centre (24) study.
534 subjects with stable COPD.
mean age: 63.4 years
male/female: 65% / 35%
mean baseline FEV1: 0.99 Litres or 37% predicted.
range: 0.29‐2.78 litres or 11.5‐76.2% predicted. Inclusion criteria:> or= 40 years of age, stable, FEV1 < or =65% predicted, FEV1/FVC < or =70 %, >10 year pack history of smoking, and using 2 prescribed therapeutic medication for COPD control in 3 months prior to entry into trial. Exclusion criteria: history of asthma, allergic rhinitis or atopy, total blood eosinophil count >500/mm3, daily use of >10mg oral prednisone within 1 month before entry. |
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| Interventions | 1) a combination of albuterol (100 mcg) and ipratropium (21 mcg), (2 puffs), four times daily. 2 ) 21 mcg ipratropium (2 puffs), four times daily. 3) 100 mcg albuterol (2 puffs), four times daily. All medication administered via MDI for 85 days. | |
| Outcomes | Primary outcomes measured on Test Day 1, 29, 57, 85 : pulmonary function tests i.e. 1)Test Day baseline FEV1, FVC 2) Test Day peak change in FEV1, FVC 3) Test Day AUC (0‐8 hr) FEV1, FVC Secondary Outcomes measured on fortnightly visits: 1) Daily PEFR‐ measured morning and evening and recorded in diary. 2) COPD symptoms (wheeze, dyspnoea, cough, chest tightness) recorded daily in symptom diary. | |
| Notes | Inclusion criteria state FEV < 65%. FEV1 range at baseline= 11.5% ‐ 76.2% predicted, suggesting some subjects with only mild disease. Unpublished standard errors obtained from Boehringer Ingelheim and converted to standard deviations. Study quality details provided by Boehringer Ingelheim. | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Computer‐generated randomisation schedule |
| Allocation concealment (selection bias) | Low risk | Third party randomisation |