背景 粪便血红蛋白免疫化学检测（FIT）如今已在结直肠肿瘤基于人群的有组织筛查项目中作为一种广泛使用的无创检测。当前所用检测的阳性阈值以粪便血红蛋白浓度（f-Hb）为依据，但所采用阈值的理由缺乏充分记载。为了解FIT在筛查项目中的全球现状使用情况，我们开展了一项国际调查，内容涵盖所用FIT的品牌、所应用的f-Hb阳性阈值以及选择依据。
Background The fecal immunochemical test for hemoglobin (FIT) is now a widely used non-invasive test in population-based organized screening programs for colorectal neoplasia. The positivity thresholds of tests currently in use are based on the fecal hemoglobin concentration (f-Hb), but the rationale for the adopted thresholds are not well documented. To understand current global usage of FIT in screening programs we conducted an international survey of the brands of FIT used, the f-Hb positivity threshold applied and the rationale for the choice.