Gastroenterology Department, Complexo Hospitalario Universitario de Ourense, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Ourense, Spain.
Instituto de Investigacién Biomédica Galicia Sur, Ourense, Spain.
United European Gastroenterol J. 2021 Mar;9(2):256-267. doi: 10.1177/2050640620949714. Epub 2021 Mar 1.
Optimizing colonoscopy resources is challenging, and information regarding performing diagnostic quantitative faecal immunochemical test (FIT) in daily clinical practice in primary health care is still limited. This study aimed to assess the sensitivity, specificity, positive predictive value and negative predictive value of varying FIT positivity thresholds on colorectal cancer (CRC) detection in primary health care.
A retrospective cohort study of 38,675 asymptomatic and symptomatic patients with a FIT (OC-Sensor™) performed between 2012 and 2016 in a primary health-care setting, using a clinical laboratory database of two Spanish areas linked with the National Health System's Hospital Discharge Records Database. The primary outcome was 2-year CRC incidence.
The mean age of the participants was 63.2 years; 17,792 (46.0%) were male. CRC prevalence was 1.7% (650/38,675). The percentage of patients with a FIT result above the threshold was 20.7% and 14.6% for 10 μg Hb/g faeces and 20 μg Hb/g faeces thresholds, respectively. Sensitivity was 90.5% (95% confidence interval 88.0%-92.5%) at a 10 μg Hb/g faeces threshold, and this decreased by 3.1% when a 20 μg Hb/g faeces threshold was used. The negative predictive value for CRC was at least 99.2% in any subgroup analysed. At a 20 μg Hb/g faeces threshold, less than one additional CRC would be missed per 1000 patients investigated, while approximately 1.3 times more colonoscopy examinations were needed to identify an incidence of CRC using the lowest threshold for any situation analysed.
In primary health care, a quantitative FIT threshold should be tailored to colonoscopy capacity and CRC prevalence in specific populations.
优化结肠镜资源具有挑战性，关于在初级保健中日常临床实践中进行诊断性定量粪便免疫化学检测（FIT）的信息仍然有限。本研究旨在评估不同 FIT 阳性阈值对初级保健中结直肠癌（CRC）检测的敏感性、特异性、阳性预测值和阴性预测值。
这是一项回顾性队列研究，纳入了 2012 年至 2016 年在初级保健环境中进行的 38675 例无症状和有症状的 FIT（OC-Sensor™）患者，使用了两个西班牙地区的临床实验室数据库，这些数据库与国家卫生系统的医院出院记录数据库相链接。主要结局是 2 年 CRC 发病率。
参与者的平均年龄为 63.2 岁；17792 人（46.0%）为男性。CRC 的患病率为 1.7%（650/38675）。FIT 结果超过阈值的患者比例分别为 20.7%和 14.6%，对应的 FIT 阈值分别为 10μg Hb/g 粪便和 20μg Hb/g 粪便。当 FIT 阈值为 10μg Hb/g 粪便时，敏感性为 90.5%（95%置信区间 88.0%-92.5%），当 FIT 阈值为 20μg Hb/g 粪便时，敏感性下降 3.1%。在任何分析的亚组中，CRC 的阴性预测值均至少为 99.2%。当 FIT 阈值为 20μg Hb/g 粪便时，每 1000 例接受检查的患者中，漏诊的 CRC 病例少于 1 例，而在任何分析的情况下，使用最低阈值进行检测时，需要进行大约 1.3 倍的结肠镜检查才能发现 CRC 的发病率。
在初级保健中，定量 FIT 阈值应根据结肠镜检查能力和特定人群中的 CRC 患病率进行调整。
