Glaxosmithkline plc, of London, presented data at the British Thoracic Society meeting in London, from a systematic analysis of 25 randomized control studies, including a meta-analysis of three key efficacy outcomes, which explored the potential impact of the particle size of different inhaled corticosteroid-containing asthma medicines, including Seretide/Advair (salmeterol/fluticasone proprionate) on patient outcomes.