Predictors of Survival in COPD: more than just the FEV1

Abstract

Chronic obstructive pulmonary disease (COPD) ranks fourth as a cause of death in the United States, behind heart disease, cancer, and stroke. Additionally, since serious co-morbidities are often present in patients with COPD, many die from other diseases such as cardiac disease or cancer. Not surprisingly, multiple factors, reflective of both respiratory disease process and the substantial co-morbidity, predict survival in the disease. As might be expected, physiologic derangements such as airflow obstruction, hypoxemia, lung hyperinflation, and exercise capacity predict survival in COPD. Anemia, cachexia and reductions in lean body mass also relate to prognosis. Perhaps less recognized is the more recent documentation that more subjective assessments, such as dyspnea and health related quality of life, are also important predictors of survival. The integration of some of the most important of these variables may provide a more comprehensive evaluation of disease severity. For example, a validated multi-dimensional disease rating that includes the body mass index (B), degree of airflow obstruction (O), dyspnea (D), and exercise capacity (E) (BODE Index) is capable of predicting COPD-related hospitalization and mortality more than its individual components.