Biomaterial Database

Performance characteristics and comparison of two immunochemical and two guaiac fecal occult blood screening tests for colorectal neoplasia. 1997

P Rozen, and J Knaani, and Z Samuel

Department of Gastroenterology, Tel Aviv Medical Center and Sackler Faculty of Medicine, Tel Aviv University, Israel.

A new immunochemical test for stool Hb, FlexSure OBT, was compared with the immunochemical HemeSelect and guaiac Hemoccult II and Hemoccult SENSA tests. Blinded development of test cards smeared with stools having added human blood showed better analytical sensitivity of FlexSure OBT (0.2 ml blood/100 g feces), than Hemoccult SENSA (> or =0.5 ml) or Hemoccult II (> or =1.0 ml). All four stool tests were prepared by 403 subjects having endoscopic examinations. The guaiac tests and FlexSure OBT were easy to prepare and develop. The positivity rate of Hemoccult SENSA was 8.7%, Hemoccult II 6%, FlexSure OBT 4.2%, and HemeSelect 3.4%. In this mainly asymptomatic (97%) population, 98% were free of clinically significant neoplasia (five had cancers, three had adenomas > or =1.0 cm). Sensitivity for cancers or adenomas > or =1.0 cm was similar for all tests (62.5-86%, NS) and Hemoccult SENSA had the lowest specificity (92% vs 95-98%, P < 0.05); but both Hemoccult II and Hemoccult SENSA had significantly lower predictive positive values (21% and 14%) than either FlexSure OBT (29%) or HemeSelect (50%) (P < 0.05). If both Hemoccult SENSA and FlexSure OBT were positive in the same subjects (1.7%), sensitivity for cancer or adenomas > or =1.0 cm (50%) was not significantly better than guaiac tests, but specificity (99.2%) and predictive positive (57%) values were improved (P < 0.05). In this population, guaiac tests were as sensitive as immunochemical tests for clinically significant colorectal neoplasia, but with significantly lower predictive positive values. A combination of a sensitive guaiac test (Hemoccult SENSA) and a specific confirmatory test for human Hb (FlexSure OBT) provided high specificity, comparable to HemeSelect.

UI	MeSH Term	Description	Entries
D007120	Immunochemistry	Field of chemistry that pertains to immunological phenomena and the study of chemical reactions related to antigen stimulation of tissues. It includes physicochemical interactions between antigens and antibodies.
D007202	Indicators and Reagents	Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)	Indicator,Reagent,Reagents,Indicators,Reagents and Indicators
D008297	Male		Males
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D009780	Occult Blood	Chemical, spectroscopic, or microscopic detection of extremely small amounts of blood.	Fecal Occult Blood Test,Blood, Occult
D011933	Reagent Kits, Diagnostic	Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.	Diagnostic Reagent Kits,Diagnostic Reagents and Test Kits,Diagnostic Test Kits,In Vitro Diagnostic Device,In Vitro Diagnostic Devices,In Vitro Diagnostic Medical Device,In Vitro Diagnostic Medical Devices,Kits, Diagnostic Reagent,Diagnostic Reagent Kit,Diagnostic Test Kit,Kit, Diagnostic Reagent,Kit, Diagnostic Test,Kits, Diagnostic Test,Reagent Kit, Diagnostic,Test Kit, Diagnostic,Test Kits, Diagnostic
D003113	Colonoscopy	Endoscopic examination, therapy or surgery of the luminal surface of the colon.	Colonoscopic Surgical Procedures,Surgical Procedures, Colonoscopic,Colonoscopic Surgery,Surgery, Colonoscopic,Colonoscopic Surgeries,Colonoscopic Surgical Procedure,Colonoscopies,Procedure, Colonoscopic Surgical,Procedures, Colonoscopic Surgical,Surgeries, Colonoscopic,Surgical Procedure, Colonoscopic
D005069	Evaluation Studies as Topic	Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies.	Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D005188	False Negative Reactions	Negative test results in subjects who possess the attribute for which the test is conducted. The labeling of diseased persons as healthy when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)	False Negative Reaction,Reaction, False Negative,Reactions, False Negative
D005189	False Positive Reactions	Positive test results in subjects who do not possess the attribute for which the test is conducted. The labeling of healthy persons as diseased when screening in the detection of disease. (Last, A Dictionary of Epidemiology, 2d ed)	False Positive Reaction,Positive Reaction, False,Positive Reactions, False,Reaction, False Positive,Reactions, False Positive