Cost Effectiveness of the Long-Acting β2-Adrenergic Agonist (LABA)/Long-Acting Muscarinic Antagonist Dual Bronchodilator Indacaterol/Glycopyrronium Versus the LABA/Inhaled Corticosteroid Combination Salmeterol/Fluticasone in Patients with Chronic Obstructive Pulmonary Disease: Analyses Conducted for Canada, France, Italy, and Portugal