即使肿瘤标志物通常是连续评估的，但少有研究报道关于肿瘤标志物的△标准。因此，本研究旨在为五种肿瘤标志物（甲胎蛋白，癌抗原19-9，癌抗原125，癌胚抗原和前列腺特异性抗原）在不同临床设置下建立实用的△参考值。我们回顾性地收集了2020年至2021年三所大学医院病人五种肿瘤标志物的近期和先前结果的对比数据。将数据分为三个亚组，即体检接受者亚组（H），门诊患者亚组（O）和住院患者亚组（I）。使用发展集（头18个月，n=179,929）确定每个测试的△百分比变化（DPC），绝对DPC（absDPC）和参考变化值（RCV）的检查限制，并通过应用验证集（最后6个月，n=66,332）进行验证和模拟。DPC和absDPC的检查限制在大多数测试中在亚组之间变化显着。同样，通过排除当前和先前结果均在参考范围内的样本计算出需要进一步评估的样本比例为0.2-2.9％（DPC下限），0.2-2.7％（DPC上限），0.3-5.6％（absDPC）和0.8-35.3％（RCV99.9％）。此外，在所有亚组的模拟中观察到了高于0.99的阴性预测值。利用真实世界的数据，我们发现DPC是评估肿瘤标志物的最合适的△检查方法，并且应根据临床设置应用肿瘤标志物的△检查限值。©2023 Walter de Gruyter GmbH，柏林/波士顿。

Few studies have reported on delta checks for tumour markers, even though these markers are often evaluated serially. Therefore, this study aimed to establish a practical delta check limit in different clinical settings for five tumour markers: alpha-fetoprotein, cancer antigen 19-9, cancer antigen 125, carcinoembryonic antigen, and prostate-specific antigen.Pairs of patients' results (current and previous) for five tumour markers between 2020 and 2021 were retrospectively collected from three university hospitals. The data were classified into three subgroups, namely: health check-up recipient (subgroup H), outpatient (subgroup O), and inpatient (subgroup I) clinics. The check limits of delta percent change (DPC), absolute DPC (absDPC), and reference change value (RCV) for each test were determined using the development set (the first 18 months, n=179,929) and then validated and simulated by applying the validation set (the last 6 months, n=66,332).The check limits of DPC and absDPC for most tests varied significantly among the subgroups. Likewise, the proportions of samples requiring further evaluation, calculated by excluding samples with both current and previous results within the reference intervals, were 0.2-2.9% (lower limit of DPC), 0.2-2.7% (upper limit of DPC), 0.3-5.6% (absDPC), and 0.8-35.3% (RCV99.9%). Furthermore, high negative predictive values >0.99 were observed in all subgroups in the in silico simulation.Using real-world data, we found that DPC was the most appropriate delta-check method for tumour markers. Moreover, Delta-check limits for tumour markers should be applied based on clinical settings.© 2023 Walter de Gruyter GmbH, Berlin/Boston.