Australian Centre for Health Services Innovation and Centre for Healthcare Transformation, School of Public Health and Social Work, Faculty of Health, Queensland University of Technology, Kelvin Grove, Australia.
Jamieson Trauma Institute, Royal Brisbane and Women's Hospital, Metro North Health, Herston, Australia.
J Am Med Inform Assoc. 2023 May 19;30(6):1103-1113. doi: 10.1093/jamia/ocad042.
Clinical prediction models providing binary categorizations for clinical decision support require the selection of a probability threshold, or "cutpoint," to classify individuals. Existing cutpoint selection approaches typically optimize test-specific metrics, including sensitivity and specificity, but overlook the consequences of correct or incorrect classification. We introduce a new cutpoint selection approach considering downstream consequences using net monetary benefit (NMB) and through simulations compared it with alternative approaches in 2 use-cases: (i) preventing intensive care unit readmission and (ii) preventing inpatient falls.
Parameter estimates for costs and effectiveness from prior studies were included in Monte Carlo simulations. For each use-case, we simulated the expected NMB resulting from the model-guided decision using a range of cutpoint selection approaches, including our new value-optimizing approach. Sensitivity analyses applied alternative event rates, model discrimination, and calibration performance.
The proposed approach that considered expected downstream consequences was frequently NMB-maximizing compared with other methods. Sensitivity analysis demonstrated that it was or closely tracked the optimal strategy under a range of scenarios. Under scenarios of relatively low event rates and discrimination that may be considered realistic for intensive care (prevalence = 0.025, area under the receiver operating characteristic curve [AUC] = 0.70) and falls (prevalence = 0.036, AUC = 0.70), our proposed cutpoint method was either the best or similar to the best of the compared methods regarding NMB, and was robust to model miscalibration.
Our results highlight the potential value of conditioning cutpoints on the implementation setting, particularly for rare and costly events, which are often the target of prediction model development research.
This study proposes a cutpoint selection method that may optimize clinical decision support systems toward value-based care.
为临床决策支持提供二分类结果的临床预测模型需要选择一个概率阈值,即“切点”,以对个体进行分类。现有的切点选择方法通常优化特定于测试的指标,包括敏感性和特异性,但忽略了正确或错误分类的后果。我们引入了一种新的切点选择方法,通过净货币收益(NMB)考虑下游结果,并通过模拟在 2 个用例中与替代方法进行了比较:(i)预防重症监护病房再入院,(ii)预防住院跌倒。
从先前的研究中纳入了成本和效果的参数估计值,用于蒙特卡罗模拟。对于每个用例,我们使用一系列切点选择方法模拟了模型指导决策的预期 NMB,包括我们新的价值优化方法。敏感性分析应用了替代事件率、模型区分度和校准性能。
与其他方法相比,考虑到预期下游结果的建议方法通常可以实现 NMB 的最大化。敏感性分析表明,在一系列场景下,它是或接近最优策略。在重症监护(患病率=0.025,接受者操作特征曲线下面积[AUC]=0.70)和跌倒(患病率=0.036,AUC=0.70)的事件率和区分度相对较低的情况下,我们提出的切点方法在 NMB 方面要么是最佳的,要么与比较方法中的最佳方法相似,并且对模型校准不良具有鲁棒性。
我们的结果强调了根据实施环境对切点进行条件化的潜在价值,特别是对于预测模型开发研究中常见的罕见且昂贵的事件。
本研究提出了一种切点选择方法,可能会优化基于价值的临床决策支持系统。