Dig Dis Sci (2007) 52:1009–1013 DOI 10.1007/s10620-006-9383-y ORIGINAL ARTICLE Performance Characteristics and Comparison of Two Fecal Occult Blood Tests in Patients Undergoing Colonoscopy Marcia Cruz-Correa · Kathleen Schultz · Sanjay Jagannath · Mary Harris · Sergey Kantsevoy · Marshall Bedine · Anthony N. Kalloo Received: 21 December 2005 / Accepted: 6 April 2006 / Published online: 16 February 2007 C  Springer Science+Business Media, Inc. 2007 Abstract We investigated the use of a new type of FOBT (EZ-Detect) that uses the blood’s pseudo-peroxidase activity as an enzymatic catalyst, in a one-step chromogen-substrate system performed by the patient. Asymptomatic patients ≥ 50 years old received three Hemoccult II (HO) cards and three EZ-Detect (EZ) packages to be used in three consecu- tive bowel movements. Sensitivity, specificity, positive pre- dictive value, and negative predictive value for detection of colorectal neoplasia was calculated. The study included 207 patients, with a mean age of 58.9 years. Diagnostic accu- racy for detection of adenomas was similar for the EZ and HO tests (66.7% vs. 71.0%; P = 0.48), while for advanced adenomas diagnostic accuracy for the EZ and HO tests was 86.0% vs. 94.2% (P = 0.01), respectively. Most patients pre- ferred the EZ test (92% vs. 8%). We conclude that the EZ test has a diagnostic profile similar to that of the HO test for identification of adenomas; however, for advanced adenomas the diagnostic accuracy was slightly better for the HO. The EZ test was preferred by most patients, which may increase colorectal cancer screening compliance. Keywords Colorectal cancer . Screening . Fecal occult blood testing . Diagnostic accuracy M. Cruz-Correa · K. Schultz · S. Jagannath · M. Harris · S. Kantsevoy · M. Bedine · A. N. Kalloo () Department of Medicine, Johns Hopkins University School of Medicine, 1830 East Monument Street, Room 420, Baltimore, Maryland 21205, USA e-mail: akalloo@jhmi.edu M. Cruz-Correa Department of Medicine, University of Puerto Rico Comprehensive Cancer Center, San Juan, Puerto Rico 00936, USA Introduction Colon cancer is the second leading cause of cancer death in the United States for men and women combined (American Cancer Society, 2005). Therefore, devising effective screen- ing programs is of paramount importance to decrease the morbidity and mortality of patients affected by this disease. The importance of screening is emphasized by the finding that patients with early colorectal cancer have a relatively high 5-year survival rate, whereas those with advanced dis- ease have a significantly decreased 5-year survival rate [1]. One of the most common colorectal cancer screening modal- ities is fecal occult blood testing (FOBT), which detects premalignant adenomas and early-stage colon cancer [2, 3]. Three randomized, controlled clinical trials have shown that both annual screening and biennial screening for occult blood in the stool significantly reduce the incidence of and the mor- tality from colorectal cancer [4–6]. Despite the widespread use of FOBT in colorectal can- cer screening, concerns remain regarding its sensitivity and specificity [7–9]. In fact, the sensitivity of the Hemoccult II (HO) test (Beckman Coulter; formerly SmithKline Diagnos- tics) has been reported to be as low as 26% for cancers and 13% for large adenomas [10]. Furthermore, the specificity of the HO test is reduced by dietary factors such as non- human hemoglobin and peroxidase-rich vegetables, which may cause false-positive results. Additionally, utilization of the current FOBT requires handling of stool by the patient, which may prove to be an obstacle for a significant number of patients. The ideal test would be one with a high sensitivity and specificity that is inexpensive and easy to use. EZ-Detect (EZ) is a type of FOBT that also uses the blood’s pseudo-peroxidase activity as an enzymatic cata- lyst. However, there appear to be several advantages of the EZ FOBT system over the HO test. First, EZ uses a newer Springer