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PubMed2000

Faecal occult blood in children with coeliac disease.

UNLABELLED: It has recently been suggested that in adults with coeliac disease, faecal blood loss may play a role in the development of iron deficiency. A group of 45 children diagnosed with coeliac disease during 1996 and 1997 were therefore prospectively evaluated for the presence of gluten in their diet, iron deficiency anaemia, and faecal occult blood. Sixty children admitted for elective surgery or asthma served as controls. Faecal occult blood was found in four iron deficient children on normal diet, of whom three were newly diagnosed. Occult blood loss disappeared in three of the four children when gluten was removed from their diet. Faecal occult blood was found in 26.7% of children on gluten-containing diet, but not in children on gluten-free diet (P = 0.01), or in control children (P = 0.001). CONCLUSION: Our data suggest that the incidence of occult blood loss in coeliac disease occurs mainly in newly diagnosed cases and responds to a gluten-free diet. Occult blood testing may not be warranted in the absence of iron deficiency anaemia nor in children with iron deficiency anaemia who are on a gluten-free diet.

Adolescent↗
PubMed1983

Spectrophotometry of occult blood in feces.

This method for measuring fecal occult blood is based on the heme-catalyzed oxidation of tetramethylbenzidine by H2O2. An aliquot of heated stool homogenate is mixed with acetic acid to chemically separate heme from globin. The heme is extracted into ethyl acetate and reacted with the reagent and H2O2 to produce a green oxidation product. The reaction is followed kinetically for 30 to 60 s at 660 nm. A660 is linearly related to the amount of hemoglobin. The lower limit of detection is 1 to 2 mg of hemoglobin per gram (wet weight) of feces. Within-day precision (CV) of the analysis for hemoglobin added to stool specimens (4 to 30 mg/g) ranged from 2.3 to 7.6%, between-day CV from 2.1 to 8.1%. Analytical recovery of hemoglobin added to fecal specimens (4 to 30 mg/g) ranged from 86.7 to 106.2%. Of the substances known to interfere with conventional dye-oxidation tests for fecal occult blood, only myoglobin and ascorbic acid interfere with hemoglobin quantification by our procedure. The test is fast, inexpensive, and easy to perform, and involves equipment available in hospital laboratories.

Benzidines↗
PubMed1997

Fecal occult blood screening in the Minnesota study: role of chance detection of lesions.

BACKGROUND: In the Minnesota Colon Cancer Control Study, annual fecal occult blood testing reduced mortality from colorectal cancer by at least 33.4%. Some attribute a large part of this reduction to chance detection of cancers by colonoscopies; rehydration of guaiac test slides greatly increased positivity and consequently the number of colonoscopies performed. This study was conducted to determine how much of the reduction resulted from chance detection. METHODS: We used a mathematical model developed by Lang and Ransohoff to estimate the proportion of the 33.4% mortality attainable by chance alone. Applying the model requires the specification of five parameters: duration of follow-up, rate of compliance with fecal occult blood testing, rate of compliance with colonoscopy, positivity rate, and efficacy of colonoscopy in reducing colorectal cancer mortality. We took values for four of the five parameters directly from the Minnesota study. For the fifth parameter, efficacy of colonoscopy, we selected a value of 60%, based on the conclusions of another study. Whereas the Lang-Ransohoff model selects persons for colonoscopy by chance alone, those with bleeding cancers would also be selected by sensitive fecal occult blood testing. We therefore adjusted the result of the Lang-Ransohoff model for this dual detectability. RESULTS: We found that 16%-25% of the reduction in colorectal cancer deaths effected by fecal occult blood testing in the Minnesota study was due to chance detection; the remainder was due to sensitive detection. CONCLUSION: Chance played a minor role in the detection of colorectal cancers by fecal occult blood testing in the Minnesota study.

Aged↗
PubMed1991

A critical analysis of the largest reported mass fecal occult blood screening program in the United States.

Fecal occult blood testing for the detection of colon cancer remains controversial. We performed a mass screening program from January 24, 1988, to February 19, 1988, with intensive media promotion, including 121 minutes of televised air time. A total of 5,000 primary practitioners were notified by mail. Hemoccult-II tests were distributed to 156,000 individuals; 55,051 (35%) were returned. Ninety-five percent of the respondents were informed of the program by television. A total of 3,375 persons (6%) tested positive for fecal occult blood; of these, 2,469 (73%) informed the center that they saw their physician to initiate a work-up. Information from physicians regarding work-ups was returned on only 1,356 (55%) patients. Diagnostic tests numbered 2,227 (1.6 tests per patient). However, 5% had no testing, 16% had a repeat Hemoccult only, and 35% had neither a barium enema nor colonoscopy performed. Thirty-six colorectal cancers and 212 polyps were identified. The predictive value (i.e., number of cancers per number of patients who tested positive) increased directly by decade. Thirty-three of 36 patients (92%) with cancer underwent either a barium enema or colonoscopy versus only 185 of 438 (42%) patients with a "negative" work-up. Cancers found were carcinoma in situ in 10 patients (29%), Dukes A in 12 (35%), Dukes B in 4 (12%), and Dukes C in 8 (24%); distant metastases were not found in any participant. Thirty-six percent of the tumors were located in either the right or transverse colon. We conclude that: (1) Screening identified early cancers. All were potentially curable and 64% were limited to the bowel wall. (2) Massive Hemoccult distribution was possible over a short interval, but patient and physician compliance was disturbingly low. (3) Total colonic evaluation is mandatory, since at least 36% of tumors were beyond the reach of the flexible sigmoidoscope. (4) Many work-ups were unnecessary (repeat Hemoccults) or inadequate, indicating a need for physician education.

Adult↗
PubMed1987

An evaluation of fecal occult blood screening in automated multiphasic health testing and services.

In the present paper, the efficacy of fecal occult blood screening in automated multiphasic health testing and services (AMHTS) is evaluated, and some problems with it are also discussed. A total of 54,735 subjects were screened for occult blood by the Shionogi slide 1-day method. According to a follow-up survey of the 715 subjects judged (+ +), 42 cases of colorectal polyp and 13 of colorectal cancer were confirmed. Eight of the 12 cases of primary colorectal cancer, excluding a case of metastatic transverse colon cancer, were located in the colon's right-side. The result may have arisen from the fact that most subjects in AMHTS are relatively young and free of symptoms. This suggests that fecal occult blood testing in AMHTS may be useful for detecting colon cancers of the right side as well as of the left. Of the nine cases of primary colorectal cancer previously screened, five had been judged (+) in previous testing. This fact indicates an especially rigorous examination of subjects judge (+) to be necessary in AMHTS. Meanwhile, of the 45 cases of gastric cancer detected by enhanced X-ray testing, only eight (17.8%) subjects were judged (+) or (+ +). It is suggested that fecal occult blood testing may not, therefore, be too effective in screening for gastric cancer.

Adult↗
PubMed1988

Screening for upper digestive tract cancer with an occult blood bead detector. Investigation of a normal north China population.

Screening of the general population for cancer of the upper digestive tract using an occult blood bead detector supplemented by fibergastroscopy was able to detect 126 cancers of the esophagus, gastric cardia, and stomach. This screening was carried out in two of the high-risk areas, Yangzhong and Wun counties, located in central eastern and north China. The occult blood bead detector, swallowed and retained in the stomach for 3 minutes, was able to sort out the suspected persons by its coloration from sky blue (+) to dark blue ( ) on removal. The subsequent fibergastroscopy could make a definite diagnosis by biopsy specimen. A preliminary trial performed on patients with established cancers was 100% (18 of 18) positive for stomach cancer and 81% (13 of 16) positive for esophageal cancer. A public survey of the high-risk areas, screening 38,073 normal persons ranging in age from 35 to 70 years, showed positive results in 9204 (24.2%) persons. Subsequent fibergastroscopy carried out in 4023 occult blood bead detector positive persons showed 126 cancers (41 of the esophagus, 46 of the gastric cardia, and 39 of the stomach). Factors influencing the cancer detection rate were sex, age, and degree of positivity of the occult blood bead detector test. Seventy per cent (89 of 126) of the cancers discovered were in an early stage. The occult blood bead detector costs the primary screened person only 30 cents and may be practical for the large-scale screening of cancer of the upper digestive tract in developing areas.

China↗
PubMed2000

Relationships between a sign of rectal bleeding and the results of an immunochemical occult blood test, and colorectal cancer.

A cross-sectional study based on medical check-up was carried out to investigate the association between signs of rectal bleeding and colorectal cancer, and the results of an immunochemical faecal occult blood test. The 9625 patients received both an immunochemical faecal occult blood test using a two-consecutive-day method and colonoscopy. They were then divided into two groups, according to the results of a self-completed questionnaire on the signs of rectal bleeding. The positivity rate of the immunochemical faecal occult blood test as well as the positive predictive value for colorectal cancer were determined in these two groups. The faecal occult blood test was positive in 9.3% of patients with rectal bleeding and in 4.4% of patients without rectal bleeding, and the positive predictive value for colorectal cancer was 0.79 and 0.27 in patients with and without rectal bleeding, respectively. This indicates a significant difference in the positivity rate (P < 0.001) as well as the positive predictive value (P < 0.05) between these two groups. The results suggest that there are positive associations between the signs of rectal bleeding and the results of immunochemical faecal occult blood test, and between the patients presenting with rectal bleeding and colorectal cancer.

Adult↗
PubMed1987

Participation in fecal occult blood screening: a critical review.

The factors that influence participation in fecal occult blood screening for colorectal cancer are poorly understood. A better understanding of these factors could lead to better screening products or to educational approaches to increase participation with currently available products. In this article, we review findings from studies that have examined the determinants of participation in fecal occult blood screening. Two components of participation are identified: initial agreement to participate and subsequent compliance with the testing procedures. We conclude that the factors that lead to agreement often differ from those that lead to compliance. Following the literature review, we discuss ways in which recent advances in attitude and behavior research might be used to improve future investigations of the determinants of participation in fecal occult blood screening. Specifically, this research suggests that investigators should focus on beliefs and attitudes associated with the perceived consequences of screening participation rather than on other types of beliefs and attitudes; measure beliefs and attitudes at the same level of specificity as behavior; and distinguish between individuals' initial agreement to participate in screening and their actual participation.

Adolescent↗
PubMed2006

Is the type of test used for mass colorectal cancer screening a determinant of compliance? A cluster-randomized controlled trial comparing fecal occult blood testing with flexible sigmoidoscopy.

BACKGROUND: The efficacy of colorectal cancer screening has been proved, and three different screening tests are recommended by international guidelines: the faecal occult blood test, flexible sigmoidoscopy and colonoscopy. While the effectiveness of a screening program depends on the compliance obtained, the role of the type of test on compliance has not yet been sufficiently studied. AIMS: To measure the effect of the type of screening test used, i.e. faecal occult blood test or flexible sigmoidoscopy, on the compliance to colorectal cancer screening programs. SUBJECTS AND METHODS: A cluster-randomized two-arm trial was conducted. We randomly assigned 20 GP's practices that had an average of 150 patients between 50 and 74 years old. RESULTS: 1449 individuals were referred to faecal occult blood test and 1538 to flexible sigmoidoscopy. The faecal occult blood test obtained higher compliance: 17.2% (95%CI 12.5-25.7) versus 7.0% (95%CI 5.7-9.0). The socio-economic status was an effect modifier of the test type: the effect of the type of test was smaller in low socioeconomic classes. CONCLUSIONS: The type of screening test used for colorectal cancer is a determinant of participation. In a low compliance area, better compliance will result from offering the faecal occult blood test than from the flexible sigmoidoscopy.

Aged↗
PubMed1999

The effect of detergents on chemical occult blood test.

OBJECTIVES: Our previous investigation showed that toilet sanitizers and their main constituents, detergents, caused false negative reactions of the immunological occult blood test. Therefore, we investigated the effects of detergents on the chemical occult blood test. MATERIALS AND METHODS: Twenty-nine kinds of detergents were added to a Hb solution and measured Hb concentration by a quantitative chemical occult blood test (modified colorimetric o tolidine method) and the results were compared with those by the immunological test. The detergents' effects on Hb spectra were also analyzed. RESULTS: The chemical test was affected slightly by most of the detergents tested although the immunological test was markedly to moderately affected. The spectrum of hemoglobin was not affected by the detergents examined except for the high concentrations of SDS and DTAB. CONCLUSION: The chemical occult blood test is affected by some detergents, but less than the immunological tests.

Benzidines↗
PubMed2004

Cost-effectiveness analysis of fecal occult blood screening for colorectal cancer.

OBJECTIVES: Clinical trials have demonstrated that fecal occult blood screening for colorectal cancer can significantly reduce mortality. However, to be deemed a priority from a public health policy perspective, any new program must prove itself to be cost-effective. The objective of this study was to assess the cost-effectiveness of screening for colorectal cancer using a fecal occult blood screening test, the Hemoccult-II, in a cohort of 100,000 asymptomatic individuals 50-74 years of age. METHODS: A decision analysis model using a Markov approach simulates the trajectory of the cohort allocated either to screening or no screening over a 20-year period through several health states. Clinical and economic data used in the model came from the Burgundy trial, French population-based studies, and Registry data. RESULTS: Modeling biennial screening versus the absence of screening over a 20-year period resulted in a 17.7 percent mortality reduction and a discounted incremental cost-effectiveness ratio of 3357 Euro per life-year gained among individuals 50-74 years of age. Sensitivity analyses performed on epidemiological and economic data showed the strong impact on the results of colonoscopy cost, of compliance to screening, and of specificity of the screening test. CONCLUSIONS: Cost-effectiveness estimates and sensitivity analyses suggest that biennial screening for colorectal cancer with fecal occult blood test could be recommended from the age of 50 until 74. Our findings support the attempts to introduce large-scale population screening programs.

Aged↗
PubMed2006

A comparative study of three fecal occult blood tests in upper gastrointestinal bleeding.

The purpose of this study was to evaluate the performance characteristics of three fecal occult blood tests (FOBTs): the chemical o-toluidine test, the immunochemical OC-Hemodia test, and the immunochromatographic Quick Chaser Occult Blood (QCOB) test, which detect human hemoglobin and transferrin simultaneously in cases of upper gastrointestinal (GI) bleeding. Included were 48 FOBT specimens in 48 consecutive admission cases of upper GI bleeding (endoscopy confirmed). We excluded those fecal specimens with an obvious tarry and bloody appearance. The QCOB test revealed the highest positive rates of 33/48 (68.8%), and significantly higher positive rates than that of the OC-Hemodia test and o-toluidine test (p < 0.025 and < 0.01, respectively). In the patient group with upper GI bleeding due to gastric and duodenal ulcers, the QCOB test had higher positive rates (68.6%) than did the o-toluidine test (34.3%) (p < 0.01). There was no fecal specimen that was positive for the o-toluidine test or OC-Hemodia test and was negative for the QCOB test. Our results reveal that the QCOB test has significantly higher positive rates of fecal occult blood than either the OC-Hemodia test or o-toluidine test. The QCOB test is better than the other two tests for detecting occult blood in patients with upper GI bleeding.

Adult↗
PubMed2000

Relationship between anal occult blood and hepatobiliary pancreatic carcinoma screening.

Cotton swab anal smear instead of stool occult blood test can not only be used as a mass screening method for colorectal cancer, but is an auxiliary way to screen hepatobiliary pancreatic carcinoma. Two hundred and twenty-three cases of hepatobiliary pancreatic carcinoma patients received anal occult blood test, of which 121 were positive (54.3%). The screening test was performed in 14,645 healthy people aged 40-60 years; 511 persons (3.4%) were positive for anal blood. Among these, six cases of digestive tract cancer were found (one oesophageal carcinoma, one gastric cardia carcinoma, two gastric carcinomas, two liver carcinomas). This suggests that when anal occult blood is positive, the patient should be scanned by ultrasonic means to rule out hepatobiliary pancreatic tumour.

Adult↗
PubMed1984

The Hemo-matic Analyzer: a new occult blood testing device.

It is now recognized that screening for fecal occult blood is useful to alert the clinician to possible colon cancer in an early stage. The guaiac impregnated card is not widely used because patients must maintain strict diets omitting red meat, peroxidase-containing foods, iron supplements, and ascorbic acid. The Hemo-matic Analyzer uses a special filter to adsorb fecal Hb which is then automatically washed free of interfering substances and quantitatively identified. The filter electrostatically binds Hb and not pepsinized blood or substances that interfere with occult blood testing. We evaluated the sensitivity of this device and compared it to the Hemoccult II test in vivo and in vitro. It was approximately six times more sensitive than Hemoccult II and was not influenced by the presence of ascorbic acid, plant peroxidase, or ingestion of a large quantity of rare red meat. In addition, the samples remained positive more than 10 wk after preparation. The Hemo-matic Analyzer is a useful new device that offers many advantages over Hemoccult card testing for screening for colon cancer.

Adult↗
PubMed2002

Detection of occult upper gastrointestinal tract bleeding: performance differences in fecal occult blood tests.

OBJECTIVE: To compare rates of detection of occult upper gastrointestinal (GI) tract bleeding by guaiac (Hemoccult II [HO]), immunochemical (HemeSelect [HS]), and heme-porphyrin (HemoQuant [HQT]) fecal occult blood tests. PATIENTS, SUBJECTS, AND METHODS: In a cross-sectional study to detect native occult upper GI tract bleeding, single stools were collected from 56 patients with iron deficiency and a proven hemorrhagic GI tract lesion. In a longitudinal study to detect simulated occult upper GI tract bleeding, 3 stool samples were serially collected from 10 clinically normal subjects after ingestion of 5 and 15 mL of autologous blood. All stool samples were subjected to blinded fecal occult blood determinations with use of the 3 tests. RESULTS: In the cross-sectional study, the HQT test detected 88% (37/42) of hemorrhagic upper GI tract lesions compared with 26% (11/42) detected by the HO test (P<.001) and 2% (1/42) by the HS test (P<.001). In the longitudinal study, all preingestion fecal occult blood test results were negative. After ingestion of 5 mL of blood, the HQT result became positive in 60% (6/10), and the HO and HS results remained negative (P=.03). After ingestion of 15 mL of blood, the HQT result became positive in all 10 cases, the HO result was positive in 6 (P=.12 vs HQT), and the HS result was positive in none (P=.002 vs HQT); all 3 stool samples collected after the 15-mL ingestion were positive in each of the 10 subjects by the HQT test but in only 1 subject by the HO test (P=.003). CONCLUSION: The HQT test detects occult upper GI tract blood loss significantly more frequently than the HO or HS test.

Adult↗
PubMed1997

Diagnostic value of immunochemical fecal occult blood test for small colorectal neoplasms.

This study was designed to assess the diagnostic value of an immunochemical fecal occult blood test for small colorectal adenomas. In a screening program based comparative study, 60 colorectal adenomas under 1 cm (small polyp group), 60 colorectal adenomas 1 cm or larger (large polyp group) and 60 colorectal cancers (cancer group) detected by occult blood screening, and 120 healthy controls (control group), served as subjects. Moreover, 50 small adenomas, 50 large adenomas and 50 cancers detected in out-patient clinics, and 100 controls, served as subjects of a hospital based comparative study. Each of these subjects was tested by an immunochemical occult blood with 3 consecutive days, after removal of these colorectal neoplasms in a screening program based study and before as well as after removal in a hospital based study, and the positivity rate of this test was evaluated among these four groups in the two comparative studies. The positivity rate in a screening program based study was 23% for small polyp group, 8% for large polyp group, 5% for cancer group and 6% for control group, respectively. Significant difference was noted between small polyp and cancer as well as control groups (p <0.01), and between small polyp and large polyp groups (p <0.05). In a hospital based study, however, there was no significant difference in the positivity rate among four groups. These results suggest that high proportion of small polyps detected by fecal occult blood test screening may not be associated with bleeding from adenomas but probably from another gastrointestinal pathology.

Adenoma↗
PubMed2004

Cost-effectiveness of colorectal cancer screening: comparison of community-based flexible sigmoidoscopy with fecal occult blood testing and colonoscopy.

BACKGROUND AND AIMS: To determine the cost-effectiveness of screening for colorectal cancer using flexible sigmoidoscopy once every 10 years, compared with annual and biennial rehydrated Hemoccult fecal occult blood testing and colonoscopy once every 10 years, or no screening. METHODS: A Markov model was developed in order to simulate the progression of a cohort of asymptomatic, average-risk individuals aged 55-64 years who were moving through a defined series of states towards death. The main outcome measures were: cases of colorectal cancer averted, colorectal cancer deaths averted, and cost per life-year saved. RESULTS: Colonoscopy averted the greatest number of cases of colorectal cancer (35%), followed by flexible sigmoidoscopy (25%), and annual (24%) and biennial (14%) fecal occult blood testing. Colonoscopy averted the greatest number of deaths from colorectal cancer (31%), followed by annual fecal occult blood testing (29%), flexible sigmoidoscopy (21%) and biennial fecal occult blood testing (19%). Flexible sigmoidoscopy was the most efficient in terms of cost per life-year saved (16,801 Australian dollars), followed by colonoscopy (19,285 Australian dollars), biennial (41,183 Australian dollars), and annual (46,900 Australian dollars) fecal occult blood testing. CONCLUSIONS: Flexible sigmoidoscopy and colonoscopy are cost-effective strategies for reducing the disease burden of colorectal cancer.

Adenoma↗
PubMed1999

Fecal occult blood testing on Trichuris-infected primary school children in northeastern peninsular Malaysia.

Stool specimens of 104 primary schoolchildren (mean+/-SD age = 8.2+/-0.3 years) were examined for helminth eggs and for occult blood to investigate the possibility that trichuriasis causes occult intestinal bleeding in the absence of the overt Trichuris dysentery syndrome. A commercially available guaiac test was used to detect fecal occult blood. Sixty-one children had Trichuris infection, 11 of whom had heavy infections (> 10,000 eggs per gram of feces [epg]), and 53 had Ascaris infections. No hookworm infection was detected. Baseline screening yielded only one weakly positive occult blood test result in a child with a light (800 epg) Trichuris infection. Serial stool occult blood testing on the 11 subjects with heavy trichuriasis and 8 uninfected controls yielded a single weakly positive result in the control group. The results provide no evidence that trichuriasis predisposes to significant occult gastrointestinal bleeding in children in the absence of the dysenteric syndrome.

Animals↗