Medical Data Research Center, Providence Health & Services, Portland, Oregon 97225, USA.
Ann Thorac Surg. 2013 Apr;95(4):1291-6. doi: 10.1016/j.athoracsur.2013.01.005. Epub 2013 Feb 28.
New York (NY) valve and valve/coronary artery bypass grafting (CABG) mortality risk models, developed from operations performed in 2007 to 2009, have just been published. These models were validated using NY data from 2004 to 2006. The authors stated that their models "should also be validated by testing them against non-New York populations." Thus, we validated the NY models with the Providence Health & Services-Swedish Health Services (PH&S-SHS) cardiac surgical data and also compared them with The Society of Thoracic Surgeons (STS) mortality risk models.
The PH&S-SHS validation data set contained 4,021 isolated valve and 2,406 valve/CABG operations, performed from 2008 to 2012. The risk models (NY logistic and score models and the STS models) were recalibrated to equalize the expected and observed number of deaths. Discrimination was tested by C statistics and calibration by Hosmer-Lemeshow statistics.
PH&S-SHS operative mortality rates were 2.6% and 5.5% in the valve and valve/CABG operations, respectively, and were lower than the NY rates. The C statistics for the NY logistic valve and valve/CABG models were 0.777 and 0.727, respectively, and were very similar for the NY score models. Calibration was good for the NY valve model (p=0.85), but not for the NY valve/CABG model (p=0.01). The STS models had better discrimination than NY models and good calibration.
The NY logistic and score models for valve operations fit the PH&S-SHS data well with acceptable discrimination and good calibration. The NY models for valve/CABG operations fit the PH&S-SHS data with acceptable discrimination and poor calibration. STS logistic regression models fit the PH&S-SHS data somewhat better.
纽约（NY）瓣膜和瓣膜/冠状动脉旁路移植术（CABG）死亡率风险模型，由 2007 年至 2009 年进行的手术开发而来，刚刚公布。这些模型使用 2004 年至 2006 年的 NY 数据进行了验证。作者指出，他们的模型“也应该通过对非纽约人群进行测试来验证”。因此，我们使用普罗维登斯健康与服务-瑞典健康服务（PH&S-SHS）心脏手术数据验证了 NY 模型，并将其与胸外科医师学会（STS）死亡率风险模型进行了比较。
PH&S-SHS 验证数据集包含 4021 例单纯瓣膜手术和 2406 例瓣膜/CABG 手术，于 2008 年至 2012 年进行。重新校准风险模型（NY 逻辑和评分模型以及 STS 模型）以平衡预期和观察到的死亡人数。通过 C 统计量测试区分度，并通过 Hosmer-Lemeshow 统计量测试校准。
PH&S-SHS 瓣膜和瓣膜/CABG 手术的手术死亡率分别为 2.6%和 5.5%，低于 NY 率。NY 逻辑瓣膜和瓣膜/CABG 模型的 C 统计量分别为 0.777 和 0.727，NY 评分模型非常相似。NY 瓣膜模型的校准效果良好（p=0.85），但 NY 瓣膜/CABG 模型的校准效果不佳（p=0.01）。STS 模型的区分度优于 NY 模型，且校准效果良好。
NY 逻辑和评分模型适用于瓣膜手术的 PH&S-SHS 数据，具有可接受的区分度和良好的校准。NY 模型适用于瓣膜/CABG 手术的 PH&S-SHS 数据，具有可接受的区分度和较差的校准。STS 逻辑回归模型对 PH&S-SHS 数据的拟合效果略好。
