Dual bronchodilation and exacerbations of COPD

In the 2016 updated version of Global Initiative for Chronic Obstructive Lung Disease (GOLD) report, it is stated that combinations of a long-acting β2-agonist (LABA) and a long-acting antimuscarinic agent (LAMA) significantly increase lung function but the impact on patient reported outcomes is limited (1). Furthermore, it also affirms that there is still too little evidence to determine if dual bronchodilation is more effective than a LAMA alone for preventing acute exacerbations of COPD (AECOPDs) (1). This sentence is inexplicable because when the 2016 version of the GOLD report was written, there was already some published evidence showing that dual bronchodilation with a LABA and a LAMA has greater efficacy in the reduction of AECOPD rates than does LAMA monotherapy (2).