Almilaji Orouba, Webb Gwilym, Maynard Alec, Chapman Thomas P, Shine Brian S F, Ellis Antony J, Hebden John, Docherty Sharon, Williams Elizabeth J, Snook Jonathon
Gastroenterology Unit, Poole Hospital, University Hospitals Dorset NHS Foundation Trust, Poole, UK.
Department of Medical Science and Public Health, Bournemouth University, Bournemouth, UK.
Diagn Progn Res. 2021 Dec 15;5(1):23. doi: 10.1186/s41512-021-00112-8.
Using two large datasets from Dorset, we previously reported an internally validated multivariable risk model for predicting the risk of GI malignancy in IDA-the IDIOM score. The aim of this retrospective observational study was to validate the IDIOM model using two independent external datasets.
The external validation datasets were collected, in a secondary care setting, by different investigators from cohorts in Oxford and Sheffield derived under different circumstances, comprising 1117 and 474 patients with confirmed IDA respectively. The data were anonymised prior to analysis. The predictive performance of the original model was evaluated by estimating measures of calibration, discrimination and clinical utility using the validation datasets.
The discrimination of the original model using the external validation data was 70% (95% CI 65, 75) for the Oxford dataset and 70% (95% CI 61, 79) for the Sheffield dataset. The analysis of mean, weak, flexible and across the risk groups' calibration showed no tendency for under or over-estimated risks in the combined validation data. Decision curve analysis demonstrated the clinical value of the IDIOM model with a net benefit that is higher than 'investigate all' and 'investigate no-one' strategies up to a threshold of 18% in the combined validation data, using a risk cut-off of around 1.2% to categorise patients into the very low risk group showed that none of the patients stratified in this risk group proved to have GI cancer on investigation in the validation datasets.
This external validation exercise has shown promising results for the IDIOM model in predicting the risk of underlying GI malignancy in independent IDA datasets collected in different clinical settings.
我们先前利用来自多塞特郡的两个大型数据集，报告了一个用于预测缺铁性贫血（IDA）患者胃肠道恶性肿瘤风险的内部验证多变量风险模型——IDIOM评分。这项回顾性观察研究的目的是使用两个独立的外部数据集验证IDIOM模型。
外部验证数据集是在二级医疗环境中，由来自牛津和谢菲尔德不同队列的不同研究人员在不同情况下收集的，分别包含1117例和474例确诊为IDA的患者。在分析之前对数据进行了匿名处理。使用验证数据集通过估计校准、区分度和临床效用的指标来评估原始模型的预测性能。
使用外部验证数据，牛津数据集对原始模型的区分度为70%（95%可信区间65, 75），谢菲尔德数据集为70%（95%可信区间61, 79）。对合并验证数据中平均、弱、灵活及跨风险组的校准分析显示，风险无低估或高估的趋势。决策曲线分析表明，在合并验证数据中，IDIOM模型具有临床价值，其净效益高于“对所有人进行检查”和“不对任何人进行检查”的策略，直至阈值为18%；使用约1.2%的风险截断值将患者分类为极低风险组，结果显示在验证数据集中，该风险组分层的患者在检查中均未被证实患有胃肠道癌症。
这项外部验证工作表明，IDIOM模型在预测不同临床环境中收集的独立IDA数据集中潜在胃肠道恶性肿瘤风险方面取得了令人鼓舞的结果。
