Patient demographics, baseline and study characteristics
| Study; first author [ref.] | Study characteristics | Duration of study weeks | Patients analysed | Drugs | Regimen of administration | Patient characteristics | Age years | Male % | Current smokers % | Smoking history pack-years | Post-bronchodilator FEV1 % pred | Jadad score |
| NCT01604278; Vincken [47] | Multicentre, randomised, double-blind, parallel-group, placebo-controlled | 12 | 432 | Glycopyrronium/indacaterol | Once daily | Moderate to severe stable COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 63.8 | 48.2 | 51.1 | 44.5 | 54.9 | 4 |
| NCT01323660, NCT01328444; Maltais [48] | Multicentre, randomised, placebo-controlled, parallel-group | 12 | 768 | Umeclidinium/vilanterol | Once daily | Moderate to severe stable COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥35% and ≤70% pred) | 62.0 | 56.4 | 62.0 | 48.1 | 51.3 | 4 |
| NCT01694771, NCT01696058; ZuWallack [49] | Multicentre, replicate, randomised, double-blind, parallel-group | 12 | 2204 | Tiotropium/olodaterol | Once daily | Moderate to severe COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 64.3 | 51.7 | 49.0 | 49.0 | 53.7 | 3 |
| NCT01727141, NCT01712516; Mahler [46] | Identical, multicentre, randomised, double-blind, parallel-group, placebo- and active-controlled | 12 | 1511 | Glycopyrronium/indacaterol | Twice daily | Stable COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 63.5 | 64.8 | 52.2 | >10 | 54.6 | 5 |
| NCT01964352, NCT02006732; Singh [50] | Multinational, replicate, randomised, double-blind, placebo-controlled, parallel group | 12 | 1169 | Tiotropium/olodaterol | Once daily | Moderate to severe COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 64.8 | 61.2 | 47.7 | >10 | 55.1 | 3 |
| NCT01313650; Donohue [51] | Multicentre, randomised, double-blind, placebo controlled, parallel-group | 24 | 1252 | Umeclidinium/vilanterol | Once daily | COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≤70% pred) | 63.3 | 70.7 | 48.2 | 46.0 | 47.6 | 4 |
| NCT01313637; Celli [52] | Multicentre, randomised, placebo-controlled, parallel-group | 24 | 1214 | Umeclidinium/vilanterol | Once daily | COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≤70% pred) | 63.1 | 65.6 | 50.8 | 44.1 | 48.3 | 4 |
| NCT01316900, NCT01316913; Decramer [53] | Multicentre, randomised, blinded, parallel-group, double-dummy | 24 | 1274 | Umeclidinium / vilanterol | Once daily | COPD (categories B or D) | 63.7 | 67.4 | 44.3 | 45.4 | 47.3 | 5 |
| NCT01437397; D’Urzo [54] | Multicentre, randomised, double-blind, placebo-controlled | 24 | 1337 | Aclidinium/formoterol | Twice daily | Moderate to severe stable COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 64.1 | 53.3 | 51.7 | 52.5 | 53.7 | 3 |
| NCT01462942; Singh [55] | Multicentre, randomised, double-blind, parallel-group, active- and placebo-controlled | 24 | 1366 | Aclidinium/formoterol | Twice daily | Moderate to severe COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 63.2 | 67.6 | 47.3 | >10 | 54.3 | 4 |
| NCT01202188; Bateman [56] | Multicentre, randomised, double-blind, parallel-group, placebo- and active-controlled | 26 | 1423 | Glycopyrronium/indacaterol | Once daily | Moderate to severe stable COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥30% and <80% pred) | 64.0 | 77.2 | 40.0 | >10 | 55.2 | 4 |
| NCT01431274, NCT01431287; Buhl [57] | Multicentre, multinational, replicate, randomised, double-blind, active-controlled, five-arm, parallel-group | 52 | 5094 | Tiotropium/olodaterol | Once daily | Moderate to very severe COPD (post-bronchodilator FEV1/FVC <0.7; and FEV1 <80% pred) | 64.0 | 72.9 | 37.0 | >10 | 50.0 | 3 |
| NCT01316887; Donohue [58] | Multicentre, randomised, double-blind, placebo-controlled, parallel-group | 52 | 177 | Umeclidinium/vilanterol | Once daily | COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 ≥35% and ≤80% pred) | 61.6 | 63.9 | NA | 41.5 | 54.6 | 4 |
| NCT01120691; Wedzicha [59] | Multicentre, randomised, double-blind, parallel-group | 64 | 1108 | Glycopyrronium/indacaterol | Once daily | Severe to very severe COPD (post-bronchodilator FEV1/FVC <0.7; FEV1 <50% pred) | 63.3 | 75.0 | 36.6 | >10 | 37.2 | 5 |
Data are presented as n, unless otherwise stated. FEV1: forced expiratory volume in 1 s; COPD: chronic obstructive pulmonary disease; FVC: forced vital capacity; NA: not available.