Department of Internal Medicine, Pennsylvania State University, Hershey, PA, USA.
Crit Care Med. 2011 May;39(5):1023-8. doi: 10.1097/CCM.0b013e31820ead31.
An independent cohort of patients with acute lung injury was used to evaluate the external validity of a simple prediction model for short-term mortality previously developed using data from Acute Respiratory Distress Syndrome Network (ARDSNet) trials.
Data for external validation were obtained from a prospective cohort study of patients with acute lung injury.
Thirteen intensive care units at four teaching hospitals in Baltimore, MD.
Five hundred and eight nontrauma patients with acute lung injury.
None.
Of the 508 patients eligible for this analysis, 234 (46%) died inhospital. Discrimination of the ARDSNet prediction model for inhospital mortality, evaluated by the area under the receiver operator characteristic curves, was 0.67 for our external validation data set vs. 0.70 and 0.68 using Acute Physiology and Chronic Health Evaluation II and the ARDSNet validation data set, respectively. In evaluating calibration of the model, predicted vs. observed inhospital mortality for the external validation data set was similar for both low-risk (ARDSNet model score = 0) and high-risk (score = 3 or 4+) patient strata. However, for intermediate-risk (score = 1 or 2) patients, observed inhospital mortality was substantially higher than predicted mortality (25.3% vs. 16.5% and 40.6% vs. 31.0% for score = 1 and 2, respectively). Sensitivity analyses limiting our external validation data set to only those patients meeting the ARDSNet trial eligibility criteria and to those who received mechanical ventilation in compliance with the ARDSNet ventilation protocol did not substantially change the model's discrimination or improve its calibration.
Evaluation of the ARDSNet prediction model using an external acute lung injury cohort demonstrated similar discrimination of the model as was observed with the ARDSNet validation data set. However, there were substantial differences in observed vs. predicted mortality among intermediate-risk patients with acute lung injury. The ARDSNet model provided reasonable, but imprecise, estimates of predicted mortality when applied to our external validation cohort of patients with acute lung injury.
利用急性肺损伤患者的独立队列评估先前使用急性呼吸窘迫综合征网络（ARDSNet）试验数据开发的短期死亡率简单预测模型的外部有效性。
外部验证数据来自急性肺损伤患者的前瞻性队列研究。
马里兰州巴尔的摩的四家教学医院的 13 个重症监护病房。
508 例非创伤性急性肺损伤患者。
无。
在符合本分析条件的 508 例患者中，234 例（46%）院内死亡。通过接收者操作特征曲线下面积评估，ARDSNet 预测模型对院内死亡率的区分度在我们的外部验证数据集为 0.67，而在急性生理学和慢性健康评估 II 和 ARDSNet 验证数据集分别为 0.70 和 0.68。在评估模型的校准方面，对于外部验证数据集，低风险（ARDSNet 模型评分=0）和高风险（评分=3 或 4+）患者亚组的预测与观察到的院内死亡率相似。然而，对于中危（评分=1 或 2）患者，观察到的院内死亡率明显高于预测死亡率（评分=1 和 2 的分别为 25.3%比 16.5%和 40.6%比 31.0%）。敏感性分析将我们的外部验证数据集仅限于符合 ARDSNet 试验入选标准的患者和符合 ARDSNet 通气方案接受机械通气的患者，并没有实质性地改变模型的区分度或改善其校准。
使用急性肺损伤队列对 ARDSNet 预测模型进行评估，结果与 ARDSNet 验证数据集观察到的模型区分度相似。然而，在急性肺损伤的中危患者中，观察到的与预测到的死亡率之间存在显著差异。ARDSNet 模型应用于急性肺损伤患者的外部验证队列时，提供了合理但不精确的预测死亡率估计。
