Figure 1.

Patient cohorts in the clinical registry of nodule status. Of 1987 patients enrolled, 585 (29%) were excluded either on the basis of being lost to follow-up (LTFU) for all reasons, including practices closed, patients changing practices, and physicians moving practices (n = 493), or on the basis of having received a confirmed cancer diagnosis (Dx) other than lung cancer, a history (Hx) of cancer (n = 78), or an invalid autoantibody test result (n = 14). Of the remaining 1402 patients (71% of the 1987), 451 (339 without cancer and 112 with cancer) had a pulmonary nodule(s) reported, whereas the remaining 951 either did not have a nodule detected by computed tomography (CT), did not have an available CT, were reported as unknown by the physician, or had a CT but with unknown results. In the 451 patients with a nodule, the nodule was calcified in 25 individuals, 75 nodules had no clear size information, and a further 55 were outside the 6-month time window, leaving 296 patients (221 without cancer and 75 with cancer) for the inclusive cohort and 269 (217 without cancer and 52 with cancer) for the exclusive cohort. The EarlyCDT-Lung positivity rates for the excluded, no-nodule, and with-nodule groups were 8%, 11%, and 25%, respectively, with the comparison of the excluded and no-nodule groups being of borderline significance (p = 0.05) and thus giving no clear evidence of bias.