Diarrhoea: SROC for cancer. SROC = Summary ROC. crc = colorectal cancer. The horizontal and vertical dimensions of the each ellipse are proportional to the square root of the number of non-diseased and diseased respectively. + shows the expected sensitivity and 1-specificity for the curve. The diagonal line joining (0,0) and (1,1) represents an ROC of no diagnostic value.
Adelstein et al. BMC Gastroenterology 2011 11:65 doi:10.1186/1471-230X-11-65