Purpose: Although current practice guidelines do not recommend screening asymptomatic patients for lung cancer, physicians may still order lung cancer screening tests. No recent national survey of health care professionals has focused on lung cancer screening. In this study, we examined the lung cancer screening practices of US primary care physicians and characteristics of those who order lung cancer screening tests.

Methods: We conducted a nationally representative survey of practicing primary care physicians in 2006-2007. Mailed questionnaires assessed the physicians' knowledge of lung cancer screening guidelines, beliefs about the effectiveness of screening tests, and ordering of screening chest radiograph, low-dose spiral computed tomography, or sputum cytology in the past 12 months. Clinical vignettes were used to assess the physicians' intentions to screen asymptomatic 50-year-old patients with varying smoking histories for lung cancer.

Results: A total of 962 family physicians, general practitioners, and general internists completed questionnaires (cooperation rate = 76.8%). Overall, 38% had ordered no lung cancer screening tests; 55% had ordered chest radiograph, 22% low-dose spiral computed tomography, and less than 5% sputum cytology. In multivariate modeling, physicians were more likely to have ordered lung cancer screening tests if they believed that expert groups recommend lung cancer screening or that screening tests are effective; if they would recommend screening for asymptomatic patients, including patients without substantial smoking exposure; and if their patients had asked them about screening.

Conclusions: Primary care physicians in the United States frequently order lung cancer screening tests for asymptomatic patients, even though expert groups do not recommend it. Primary care physicians and patients need more information about lung cancer screening's evidence base, guidelines, potential harms, and costs to avert inappropriate ordering.