PURPOSE: COPD is the 4th leading cause of death in the United States and like lung cancer, smoking is its major risk factor. Although more than 30 million Americans have airflow obstruction, less than half are diagnosed with COPD and fewer are treated. The National Lung Screening Trial (NLST) is a randomized trial comparing annual chest radiographs (CXR) with CT scans for the early detection of lung cancer. We hypothesized that among the NLST population, COPD would be under recognized.
METHODS: We obtained demographic and medical information and performed spirometry on NLST enrollees undergoing an annual CXR/CT. Subjects were classified into Global Initiative for Obstructive Lung Disease (GOLD) stages using modified (pre-bronchodilator) criteria. We then determined the fraction that had received a physician diagnosis of COPD and were treated for the disease.
RESULTS: 449 subjects were enrolled and 236 (53%) had airway obstruction (FEV1/FVC<0.70). 163 (36%) had at least GOLD stage II disease (FEV1<80% predicted). Table 1 shows the demographic and lung function data for those in each stage. 80/236 (34%) carried a diagnosis of COPD while only 42/236 (18%) were treated. Diagnosis (67% vs. 29%, p<0.0001) and treatment (51% vs. 12%, p<0.0001) were more common among those with more severe airflow obstruction (stage III/IV vs. stage I/II). Neither race nor sex predicted diagnosis or treatment.
CONCLUSION: COPD is under-recognized and under-treated in the NLST population. Among these heavy smokers, significant airflow obstruction occurred more frequently than would be expected based on traditional teaching.
CLINICAL IMPLICATIONS: Clinicians should be more aware of the possibility of COPD among patients they feel are at risk for lung cancer.
DISCLOSURE: Chad Miller, None.