Comparative evaluation of immunochemical fecal occult blood tests for colorectal adenoma detection. Ann Intern Med

Background: Different immunochemical fecal occult blood tests (FOBTs) have been proposed for noninvasive colorectal cancer screening. Large-scale, colonoscopy-based screening studies that allow evaluation of these tests for the detection of precursor lesions are scarce. Objective: To determine and compare performance characteristics of 6 qualitative immunochemical FOBTs for identifying colorectal adenomas among adults who attended screening colonoscopy ex-aminations. Design: Prospective screening study from January 2006 to Decem-ber 2007. Setting: 20 gastroenterology practices in Germany that did screen-ing colonoscopy. Patients: 1319 participants at average risk for colorectal neoplasia who were undergoing screening colonoscopy (mean age, 63 years; 50 % men). Measurements: 6 different qualitative immunochemical FOBTs were done with stool samples collected before bowel preparation for colonoscopy. Performance characteristics (sensitivity, specificity, predictive values, and likelihood ratios) of tests were measured by comparing test results with findings on colonoscopy. Technicians who read the tests were blinded to colonoscopy results, and colonoscopists were blinded to FOBT results. Results: Overall, 405 participants (31%) had an adenoma and 130 participants (10%) had an advanced adenoma. Performance char-acteristics varied widely among tests. For the 2 best-performing tests (immoCARE-C [CAREdiagnostica, Voerde, Germany] and FOB advanced [ulti med, Ahrensburg, Germany]), the sensitivity for de-tection of advanced adenomas was 25 % (95 % CI, 18 % to 34%) and 27 % (CI, 20 % to 35%), respectively; specificity was 97 % (CI