Clinical course of chronic obstructive pulmonary disease: review of therapeutic interventions.

Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease in which patients experience a progressive decline in lung function. Based on clinical evidence, the management of COPD should focus on (1) earlier diagnosis; (2) risk reduction through smoking cessation, decreased exposure to inhaled irritants, and immunization against respiratory pathogens; (3) symptom reduction with pharmacotherapy and pulmonary rehabilitation; (4) decreasing complications by reducing exacerbations and improving pulmonary function; and (5) improving health-related quality of life (HRQOL). Smoking cessation has been shown to slow lung function decline and to reduce mortality--including deaths due to lung cancer, other respiratory disease (including COPD), and cardiovascular disease. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) and the American Thoracic Society and European Respiratory Society (ATS/ERS) guidelines advocate interventions according to the severity of COPD and recommend initiation of maintenance long-acting bronchodilator therapy in patients with moderate disease. However, recent evidence from a post hoc analysis of randomized controlled trials of tiotropium suggests that initiation of long-acting bronchodilator therapy at earlier stages of disease may also provide improvements in lung function and HRQOL. The results of ongoing long-term studies may soon provide evidence that in addition to relieving symptoms and improving patient HRQOL, specific pharmacologic therapies may also alter the clinical course of COPD.