ABSTRACT
Chronic obstructive pulmonary disease (COPD) is an increasingly important major public health concern in the United States and worldwide. The disease affects an estimated 16 million people in the United States or approximately 5% of the population and anywhere from 15% to 35% of heavy cigarette smokers are affected (Rennard and Vestbo, 2006; Rabe et al., 2007). In fact, COPD is the third leading cause of death in the United States and fourth leading cause of death worldwide. It is estimated that 170,000 Americans die of COPD annually in the United States. In addition to its effects on the mortality and morbidity of cigarette smokers, COPD also represents a serious nancial burden upon the health system of the United States, costing in excess of $193 billion dollars a year. It is estimated that only 50% of cases have been formally diagnosed. Two important factors appear to explain the signicant underdiagnosis of the disease: (1) Symptoms develop only relatively late in the disease and (2) direct testing of lung function by the technique of spirometry is not performed routinely in all smokers.
