Background We aimed to improve the sensitivity of immunochemical fecal occult blood test (I-FOBT) to screen colorectal neoplasm among average-risk adults.Methods This is a diagnostic cohort study.All health examination participants receiving a single qualitative I-FOBT and a screening colonoscopy from January 2010 to June 2011 were included.Stool specimens were collected for I-FOBT before colonoscopy.Using pathology as gold standard,significant colorectal neoplasm was defined as advanced adenoma or malignancy.Results A total of 1 007 health examinees were identified.Fifty-five (5.5％) had borderline positive (+/-) I-FOBT,while 38 (3.8％) had positive I-FOBT.Twenty-four (2.4％) had advanced adenoma,and five (0.5％) had carcinoma.Using borderline positive I-FOBT as cutoff value,the sensitivity and specificity for significant colorectal neoplasm were 34.5％ (95％ confidence interval (CI) 19.9％-52.7％) and 91.5％ (95％ Cl89.6％-93.1％),respectively.If combined with advanced age,high blood pressure (BP),and abdominal obesity,a fulfillment of either two criteria further increased the sensitivity to 72.4％ (95％ Cl54.3％-85.3％) with a specificity of 68.8％ (95％ Cl65.8％-71.6％).Conclusion The sensitivity of a single qualitative I-FOBT for the detection of significant colorectal neoplasm can be increased by coupling with age,BP,and abdominal obesity.

BACKGROUNDWe aimed to improve the sensitivity of immunochemical fecal occult blood test (I-FOBT) to screen colorectal neoplasm among average-risk adults.

METHODSThis is a diagnostic cohort study. All health examination participants receiving a single qualitative I-FOBT and a screening colonoscopy from January 2010 to June 2011 were included. Stool specimens were collected for I-FOBT before colonoscopy. Using pathology as gold standard, significant colorectal neoplasm was defined as advanced adenoma or malignancy.

RESULTSA total of 1 007 health examinees were identified. Fifty-five (5.5%) had borderline positive (+/-) I-FOBT, while 38 (3.8%) had positive I-FOBT. Twenty-four (2.4%) had advanced adenoma, and five (0.5%) had carcinoma. Using borderline positive I-FOBT as cutoff value, the sensitivity and specificity for significant colorectal neoplasm were 34.5% (95% confidence interval (CI) 19.9%-52.7%) and 91.5% (95% CI 89.6%-93.1%), respectively. If combined with advanced age, high blood pressure (BP), and abdominal obesity, a fulfillment of either two criteria further increased the sensitivity to 72.4% (95% CI 54.3%-85.3%) with a specificity of 68.8% (95% CI 65.8%-71.6%).

CONCLUSIONThe sensitivity of a single qualitative I-FOBT for the detection of significant colorectal neoplasm can be increased by coupling with age, BP, and abdominal obesity.

Adult ; Aged ; Aged, 80 and over ; Colorectal Neoplasms ; diagnosis ; Female ; Humans ; Male ; Mass Screening ; Middle Aged ; Occult Blood ; Sensitivity and Specificity ; Young Adult