Abstract：
BACKGROUND: We determined the impact of an increased two-stool faecal immunochemical test (FIT) cut-off on colonoscopy positivity and relative sensitivity and specificity in the randomized controlled screening trial screening of Swedish colons conducted in Sweden.
METHODS: We performed a cross-sectional analysis of participants in the FIT arm that performed FIT between March 2014 and 2020 within the study registered with ClinicalTrials.gov, NCT02078804, who had a faecal haemoglobin concentration of at least 10 µg/g in at least one of two stool samples and who underwent a colonoscopy (n = 3841). For each increase in cut-off, we computed the positive predictive value (PPV), numbers needed to scope (NNS), sensitivity and specificity for finding colorectal cancer (CRC) and advanced neoplasia (AN; advanced adenoma or CRC) relative to cut-off 10 µg/g.
RESULTS: The PPV for AN increased from 23.0% (95% confidence intervals [CI]: 22.3%-23.6%) at cut-off 10 µg/g to 28.8% (95% CI: 27.8%-29.7%) and 33.1% (95% CI: 31.9%-34.4%) at cut-offs 20 and 40 µg/g, respectively, whereas the NNS to find a CRC correspondingly decreased from 41 to 27 and 19. The PPV for AN was higher in men than women at each cut-off, for example 31.5% (95% CI: 30.1%-32.8%) in men and 25.6% (95% CI: 24.3%-27.0%) in women at 20 µg/g. The relative sensitivity and relative specificity were similar in men and women at each cut-off.
CONCLUSIONS: A low cut-off of around 20-40 µg/g allows detection and removal of many AN compared to 10 µg/g while reducing the number of colonoscopies in both men and women.
METHODS: We performed a cross-sectional analysis of participants in the FIT arm that performed FIT between March 2014 and 2020 within the study registered with ClinicalTrials.gov, NCT02078804, who had a faecal haemoglobin concentration of at least 10 µg/g in at least one of two stool samples and who underwent a colonoscopy (n = 3841). For each increase in cut-off, we computed the positive predictive value (PPV), numbers needed to scope (NNS), sensitivity and specificity for finding colorectal cancer (CRC) and advanced neoplasia (AN; advanced adenoma or CRC) relative to cut-off 10 µg/g.
RESULTS: The PPV for AN increased from 23.0% (95% confidence intervals [CI]: 22.3%-23.6%) at cut-off 10 µg/g to 28.8% (95% CI: 27.8%-29.7%) and 33.1% (95% CI: 31.9%-34.4%) at cut-offs 20 and 40 µg/g, respectively, whereas the NNS to find a CRC correspondingly decreased from 41 to 27 and 19. The PPV for AN was higher in men than women at each cut-off, for example 31.5% (95% CI: 30.1%-32.8%) in men and 25.6% (95% CI: 24.3%-27.0%) in women at 20 µg/g. The relative sensitivity and relative specificity were similar in men and women at each cut-off.
CONCLUSIONS: A low cut-off of around 20-40 µg/g allows detection and removal of many AN compared to 10 µg/g while reducing the number of colonoscopies in both men and women.
摘要：
背景：在瑞典进行的瑞典结肠随机对照筛选试验中，我们确定了增加双便粪便免疫化学试验（FIT）截止值对结肠镜检查阳性和相对敏感性和特异性的影响。
方法：我们对2014年3月至2020年期间在ClinicalTrials.gov注册的研究中进行FIT的FIT组参与者进行了横断面分析，NCT02078804，在两个粪便样本中至少有一个粪便血红蛋白浓度至少为10µg/g，并且接受了结肠镜检查（n=3841）。对于截止值的每增加,我们计算了阳性预测值(PPV)，范围所需的数字(NNS)，相对于截止值10µg/g，发现结直肠癌（CRC）和晚期瘤形成（AN；晚期腺瘤或CRC）的敏感性和特异性。
结果：AN的PPV从截止10µg/g时的23.0％（95％置信区间[CI]：22.3％-23.6％）增加到截止20和40µg/g时的28.8％（95％CI：27.8％-29.7％）和33.1％（95％CI：31.9％-34.4％），分别,而发现CRC的NNS相应地从41降至27和19。在每个截止日期，男性的ANPPV高于女性，例如，在20µg/g时，男性为31.5%(95%CI:30.1%-32.8%)，女性为25.6%(95%CI:24.3%-27.0%)。在每个截止点，男性和女性的相对敏感性和相对特异性相似。
结论：与10µg/g相比，约20-40µg/g的低截止值允许检测和去除许多AN，同时减少了男性和女性的结肠镜检查次数。
方法：我们对2014年3月至2020年期间在ClinicalTrials.gov注册的研究中进行FIT的FIT组参与者进行了横断面分析，NCT02078804，在两个粪便样本中至少有一个粪便血红蛋白浓度至少为10µg/g，并且接受了结肠镜检查（n=3841）。对于截止值的每增加,我们计算了阳性预测值(PPV)，范围所需的数字(NNS)，相对于截止值10µg/g，发现结直肠癌（CRC）和晚期瘤形成（AN；晚期腺瘤或CRC）的敏感性和特异性。
结果：AN的PPV从截止10µg/g时的23.0％（95％置信区间[CI]：22.3％-23.6％）增加到截止20和40µg/g时的28.8％（95％CI：27.8％-29.7％）和33.1％（95％CI：31.9％-34.4％），分别,而发现CRC的NNS相应地从41降至27和19。在每个截止日期，男性的ANPPV高于女性，例如，在20µg/g时，男性为31.5%(95%CI:30.1%-32.8%)，女性为25.6%(95%CI:24.3%-27.0%)。在每个截止点，男性和女性的相对敏感性和相对特异性相似。
结论：与10µg/g相比，约20-40µg/g的低截止值允许检测和去除许多AN，同时减少了男性和女性的结肠镜检查次数。
