Figure 1.

Participant recruitment flow diagram up to baseline screening low-dose computed tomography. * = Former smoker is defined as one who has stopped smoking for ≥1 year. ** = Pack-year is defined as number of packs of cigarettes smoked per day multiplied by the number of years smoked. (If participant ceased smoking for ≥6 mo interval, the time will be subtracted from the total duration of smoking in 0.5-year increments.) # = Any medical condition that, in the investigator’s opinion, may jeopardize the subject’s safety during participation in the study or mean that the subject is unlikely to benefit from screening due to shortened life expectancy; and may include severe cardiac disease (e.g., unstable angina, congestive cardiac failure), acute or chronic respiratory failure, home oxygen therapy for advanced lung disease, bleeding disorders, etc. CT = computed tomography; ECOG performance status = Eastern Cooperative Oncology Group (51); LDCT = low-dose computed tomography; PLCO = Prostate, Lung, Colorectal and Ovarian; USPSTF = U.S. Preventive Services Task Force.