ABSTRACT
The rate of forced expiratory volume in one second (FEV1) decline is a physiological measure of disease progression and is widely used as an outcome measure for clinical trials of chronic obstructive pulmonary disease (COPD) treatment because it is predictive of morbidity, mortality, quality of life, and hospitalization rates (1). Estimates of the decline in FEV1 in nonsmoking men and women vary between 29.6 and 19.6 mL/yr (2,3). The rate of decline classically accelerates with age, but might appear to slow at the very upper end of the age range, as only those people with the slower rates of decline survive.
