 Chronic obstructive pulmonary disease COPD represents a growing public health problem and is now the third leading cause of death in the United States. The risk of exacerbations, hospitalizations and death in patients with COPD tends to increase with increasing severity of airflow limitation. However, the correlation between forced expiratory volume in 1 second FEV1, symptoms, and health-related quality of life is weak. The shortcomings of using airflow limitation alone to assess the clinical severity of COPD led the Global Initiative for Chronic Obstructive Lung Disease GOLD committee to develop a potentially more clinically meaningful approach to assess the impact of COPD on the patient. The GOLD committee has subsequently proposed a model for pharmacologic therapy of patients with stable COPD i.e. those not currently experiencing a COPD exacerbation according to GOLD risk group. The therapeutic recommendations proposed by GOLD are widely cited as a strategy for selecting therapy even though this model is predominantly based on expert opinion. 