Sensitivity, specificity, and positive predictivity of the Hemoccult test in screening for colorectal cancers. The University of Minnesota's Colon Cancer Control Study
Mandel, J.S.; Bond, J.H.; Bradley, M.; Snover, D.C.; Church, T.R.; Williams, S.; Watt, G.; Schuman, L.M.; Ederer, F.; Gilbertsen, V.
Gastroenterology 97(3): 597-600
1989
ISSN/ISBN: 0016-5085 PMID: 2666251 Document Number: 346527
Data are presented on the sensitivity, specificity, and positive predictivity of the Hemoccult test based on the experience of the Minnesota Colon Cancer Control Study, a randomized clinical trial to determine whether the use of the Hemoccult test can reduce mortality from colorectal cancer. Rehydrating the slides with a drop of water before processing resulted in an increase in positivity (2.4% to 9.8%), and sensitivity (80.8% to 92.2%) but a decrease in specificity (97.7% to 90.4%) and positive predictivity (5.6% to 2.2%). The effects of age and sex were also evaluated. The test was less specific for men than women (p = 0.03). Specificity was highest for those < 60 yr of age and decreased with increasing age (p = 0.05). The positive predictivity increased with age from 1.6% for those under 60 yr to 3.6% for those over 70 yr (p = 0.0004).