目的探讨行下肢骨折手术的老年患者术后2年内死亡的预测因素。方法收集择期行下肢骨折手术的老年患者(年龄≥65岁)的临床资料,根据术后2年内的生存状况,将患者分为生存组和死亡组。对两组间差异有统计学意义的因素进行多因素Cox回归分析...目的探讨行下肢骨折手术的老年患者术后2年内死亡的预测因素。方法收集择期行下肢骨折手术的老年患者(年龄≥65岁)的临床资料,根据术后2年内的生存状况,将患者分为生存组和死亡组。对两组间差异有统计学意义的因素进行多因素Cox回归分析,筛选出2年内死亡的预测因素,再通过受试者工作特征曲线(receiver operation characteristic,ROC)及曲线下面积(area under the curve,AUC)评估其预测能力。结果最终纳入372例患者资料进行统计分析,其中2年内死亡55例(病死率为14.7%)。Cox回归分析结果显示,年龄≥75岁(HR:2.155,95%CI:1.093~4.247)、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级≥3级(HR:2.978,95%CI:1.242~7.183)、Charlson合并症指数(Charlson Comorbidity Index,CCI)评分≥2(HR:4.649,95%CI:2.467~8.761)、术前贫血(HR:2.050,95%CI:1.066~3.943)及术后住院期间发生心脑血管事件(HR:3.026,95%CI:1.491~6.140)为该类患者术后2年内死亡的预测因素,其AUC分别为0.677、0.733、0.700、0.584和0.658。上述5种因素联合预测的AUC为0.858,显著高于任意单一因素;ASA分级≥3级的预测敏感度最高(敏感度87.3%);CCI评分≥2的预测特异度最强(特异度92.7%)。结论老年患者行下肢骨折手术后2年内死亡的预测因素为年龄≥75岁、ASA分级≥3级、CCI评分≥2、术前贫血和术后住院期间发生心脑血管事件,且5种因素联合预测具有更高的预测价值,提示有针对性的进行围术期干预可能有助于提高患者长期生存率。展开更多
In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied eith...In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nu-merically,such as Poincaré map,Lyapunov exponents and Lyapunov dimension. Based on this flow,a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients.展开更多
文摘目的探讨行下肢骨折手术的老年患者术后2年内死亡的预测因素。方法收集择期行下肢骨折手术的老年患者(年龄≥65岁)的临床资料,根据术后2年内的生存状况,将患者分为生存组和死亡组。对两组间差异有统计学意义的因素进行多因素Cox回归分析,筛选出2年内死亡的预测因素,再通过受试者工作特征曲线(receiver operation characteristic,ROC)及曲线下面积(area under the curve,AUC)评估其预测能力。结果最终纳入372例患者资料进行统计分析,其中2年内死亡55例(病死率为14.7%)。Cox回归分析结果显示,年龄≥75岁(HR:2.155,95%CI:1.093~4.247)、美国麻醉医师协会(American Society of Anesthesiologists,ASA)分级≥3级(HR:2.978,95%CI:1.242~7.183)、Charlson合并症指数(Charlson Comorbidity Index,CCI)评分≥2(HR:4.649,95%CI:2.467~8.761)、术前贫血(HR:2.050,95%CI:1.066~3.943)及术后住院期间发生心脑血管事件(HR:3.026,95%CI:1.491~6.140)为该类患者术后2年内死亡的预测因素,其AUC分别为0.677、0.733、0.700、0.584和0.658。上述5种因素联合预测的AUC为0.858,显著高于任意单一因素;ASA分级≥3级的预测敏感度最高(敏感度87.3%);CCI评分≥2的预测特异度最强(特异度92.7%)。结论老年患者行下肢骨折手术后2年内死亡的预测因素为年龄≥75岁、ASA分级≥3级、CCI评分≥2、术前贫血和术后住院期间发生心脑血管事件,且5种因素联合预测具有更高的预测价值,提示有针对性的进行围术期干预可能有助于提高患者长期生存率。
基金Project supported by the National Natural Science Foundation of China (No. 50475109)the Natural Science Foundation of Gansu Province (No. 3ZS-042-B25-049), China
文摘In this paper,a new nonlinear autonomous system introduced by Chlouverakis and Sprott is studied further,to present very rich and complex nonlinear dynamical behaviors. Some basic dynamical properties are studied either analytically or nu-merically,such as Poincaré map,Lyapunov exponents and Lyapunov dimension. Based on this flow,a new almost-Hamilton chaotic system with very high Lyapunov dimensions is constructed and investigated. Two new nonlinear autonomous systems can be changed into one another by adding or omitting some constant coefficients.
