The Effect of the Variability in Fecal Immunochemical Test Sample Collection Technique on Clinical Performance

Abstract Background: Fecal immunochemical test (FIT) performance can be affected by post-collection variables. Collection technique might also affect fecal hemoglobin concentration (f-Hb). Variation in quantity of feces collected samples returned a colorectal cancer detection program, and the effects under-sampling, were assessed. Methods: devices obtained from patients undergoing FIT assessed for color (in five classes) buffer, mass, f-Hb. Associations between these examined an vitro study on Hb-spiked feces. Variables possibly associated with under-sampling investigated using multivariable logistic regression. The effect low sample mass clinical (false-negative results) was determined. Results: Of 6,898 3,449 individuals (46.9% male, median age: 65.3 years), buffer lightest 362 (5.2%), darkest 420 (6.1%). Samples had significantly lower f-Hb compared all darker classes (P < 0.001). Mass recorded 650 devices: colored 0.05). correlation confirmed (r = 0.897, P Low not age, sex, or technical factors > Under-sampling related to false-negative results advanced adenoma, but neoplasia inflammatory bowel disease. Conclusions: Wide variation existed amount collected. measured may increase results. Impact: Color could used identify inadequate sampling.