Hukkelhoven Chantal W P M, Steyerberg Ewout W, Habbema J Dik F, Farace Elana, Marmarou Anthony, Murray Gordon D, Marshall Lawrence F, Maas Andrew I R
Center for Clinical Decision Sciences, Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
J Neurotrauma. 2005 Oct;22(10):1025-39. doi: 10.1089/neu.2005.22.1025.
The early prediction of outcome after traumatic brain injury (TBI) is important for several purposes, but no prognostic models have yet been developed with proven generalizability across different settings. The objective of this study was to develop and validate prognostic models that use information available at admission to estimate 6-month outcome after severe or moderate TBI. To this end, this study evaluated mortality and unfavorable outcome, that is, death, and vegetative or severe disability on the Glasgow Outcome Scale (GOS), at 6 months post-injury. Prospectively collected data on 2269 patients from two multi-center clinical trials were used to develop prognostic models for each outcome with logistic regression analysis. We included seven predictive characteristics-age, motor score, pupillary reactivity, hypoxia, hypotension, computed tomography classification, and traumatic subarachnoid hemorrhage. The models were validated internally with bootstrapping techniques. External validity was determined in prospectively collected data from two relatively unselected surveys in Europe (n = 796) and in North America (n = 746). We evaluated the discriminative ability, that is, the ability to distinguish patients with different outcomes, with the area under the receiver operating characteristic curve (AUC). Further, we determined calibration, that is, agreement between predicted and observed outcome, with the Hosmer-Lemeshow goodness-of-fit test. The models discriminated well in the development population (AUC 0.78-0.80). External validity was even better (AUC 0.83-0.89). Calibration was less satisfactory, with poor external validity in the North American survey (p < 0.001). Especially, observed risks were higher than predicted for poor prognosis patients. A score chart was derived from the regression models to facilitate clinical application. Relatively simple prognostic models using baseline characteristics can accurately predict 6-month outcome in patients with severe or moderate TBI. The high discriminative ability indicates the potential of this model for classifying patients according to prognostic risk.
创伤性脑损伤（TBI）后结局的早期预测具有多种重要意义，但尚未开发出在不同环境中均具有可靠通用性的预后模型。本研究的目的是开发并验证预后模型，该模型利用入院时可得信息来估计重度或中度TBI后的6个月结局。为此，本研究评估了伤后6个月时的死亡率和不良结局，即格拉斯哥预后量表（GOS）评定的死亡、植物状态或严重残疾。通过逻辑回归分析，利用来自两项多中心临床试验的2269例患者的前瞻性收集数据，为每种结局建立预后模型。我们纳入了七个预测特征——年龄、运动评分、瞳孔反应性、低氧血症、低血压、计算机断层扫描分类和创伤性蛛网膜下腔出血。采用自抽样技术在内部对模型进行验证。在欧洲（n = 796）和北美（n = 746）两项相对未经过筛选的前瞻性收集调查数据中确定外部效度。我们采用受试者工作特征曲线（ROC）下面积评估模型的判别能力，即区分不同结局患者的能力。此外，我们采用Hosmer-Lemeshow拟合优度检验确定校准度，即预测结局与观察结局之间的一致性。模型在开发人群中具有良好的判别能力（AUC为0.78 - 0.80）。外部效度甚至更佳（AUC为0.83 - 0.89）。校准度不太理想，在北美调查中外部效度较差（p < 0.001）。特别是，对于预后不良的患者，观察到的风险高于预测值。从回归模型得出了评分表以方便临床应用。使用基线特征的相对简单的预后模型能够准确预测重度或中度TBI患者的6个月结局。高判别能力表明该模型具有根据预后风险对患者进行分类的潜力。
