Fig. 4From: Long-acting bronchodilators improve exercise capacity in COPD patients: a systematic review and meta-analysisEfficacy of long-acting bronchodilators on dyspnea. I2 55.1% (95% CI 26.8–69.4%). Error bars represent 95% confidence intervals. For Ume/Vil †: study n. 1222.37; *: study n. 1222.38. For Olo †: study n. 418; *: study n. 417Back to article page