Fig. 4From: Decline of COPD exacerbations in clinical trials over two decades – a systematic review and meta-regressionEstimated annual reduction in exacerbation rates (see also Tables 2,3,4). In the “overall” model, the estimated decrease is at 6.3% (95% CI (3.9, 8.7)) per calender year. The estimates based on the two disjoint subgroups of placebo controls are very similar, and adjusting for baseline mean SGRQ score or FEV1 also leads to consistent effectsBack to article page