Receiver operating characteristic (ROC) curves of FIT for the detection of adenocarcinoma (solid line) and significant colorectal disease (dashed line). Black dots represent a single estimated true positive/false positive rate of gFOB for adenocarcinoma (ACa) and significant colorectal disease (SCD). Cross-hatches correspond to the true positive/false positive rate estimates for thresholds of (7 µg/g, 10 µg/g, 20 µg/g and 50 µg/g). AUC, area under the curve; FIT, faecal immunochemical test; gFOB, guaiac faecal occult blood.