Clinically meaningful outcomes in patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is characterized by chronic airflow limitation, gas exchange abnormalities, hyperinflation, and other pathophysiologic events. However, patients are usually unaware of these physical changes and only seek medical attention when distressing symptoms, such as dyspnea and exercise limitation, begin to appear. Therefore, it is reasonable to directly assess these clinical areas of importance to the patient, both as determinants of the impact of the disease process and as outcomes following intervention. Although many of the physiologic abnormalities of COPD are only partially or poorly reversible with treatment, dyspnea, exercise performance, and health status often show impressive gains with therapy. Incorporating clinically relevant outcome assessments complements traditional physiologic measurements and provides the clinician with a yardstick to determine whether a particular intervention is causing a meaningful improvement in the patient. This article discusses these clinical assessments and provides specific examples of their applicability and usefulness in treating patients with COPD.