基于双重稳健估计方法的非小细胞肺癌治疗过程对院内死亡的因果效应研究

Research on the causal effects of non-small cell lung cancer treatment process on in-hospital mortality based on double robust estimation method

目的基于双重稳健估计(Doubly robust,DR)方法估计非小细胞肺癌治疗过程对院内死亡的因果效应大小,为降低非小细胞肺癌院内死亡率提供参考依据。方法依据非小细胞肺癌治疗质量评价体系,计算治疗过程指标的使用率,以治疗过程质量均值得分为界限将患者划分为高质量组与低质量组。以院内死亡为结局指标,采用倾向性评分逆概率加权(Inverse probability of treatment weighting,IPTW)法校正的Kaplan-Meier法及Cox回归,分析治疗过程质量对非小细胞肺癌院内死亡的影响;结合DR估计治疗过程对院内死亡的因果效应大小。结果治疗过程指标使用率的中位数为66.88%,患者治疗过程质量得分为0.270±0.124,其中高质量组为0.358±0.069,低质量组为0.158±0.081。经过IPTW法加权后,患者基线特征标准化平均差(Standardized mean difference,SMD)减小;IPTW前后两组患者生存曲线间差异具有统计学意义(P<0.05),高质量组患者的预后优于低质量组患者(IPTW前:HR=0.367,95%CI:0.275~0.491;IPTW后:HR=0.228,95%CI:0.167~0.312)。与低质量组相比,高质量组患者治疗过程对院内死亡的平均因果效应大小为-0.026。结论DR可弥补logistic或IPTW的不足,规避模型出错的风险,可以获得治疗过程质量对院内死亡的因果效应。医疗实践中应提高治疗过程指标的使用率,从而改善患者预后;因果效应研究提示,除治疗过程外,影响院内死亡的其他因素也是不可忽略的。

Objective The aim of this study was to estimate the causal effects of non-small cell lung cancer(NSCLC)treatment process on in-hospital mortality based on the double robust estimation(DR)method,and provide a reference basis for reducing in-hospital mortality of NSCLC.Methods According to the quality evaluation system of NSCLC treatment,the utilization rate of treatment process indicators was calculated,and patients were divided into the high-quality or low-quality groups based on the average score of treatment process quality.In-hospital mortality was used as the outcome indicator,Kaplan-Meier method and Cox regression adjusted for propensity score inverse probability of treatment weighting(IPTW)correction were used to analyze the impact of treatment process quality on in-hospital mortality in NSCLC.DR was combined to estimate the causal effects of the treatment process on in-hospital mortality.Results The median utilization rate of treatment process indicators was 66.88%,and the mean and standard deviation of patients′treatment process quality scores were 0.270±0.124,including 0.358±0.069 in the high-quality group,and 0.158±0.081 in the low-quality group.After the IPTW weighting,the standardized mean difference(SMD)of patients′baseline characteristics decreased;The difference in survival curves between the two groups of patients before and after ITPW was statistically significant(P<0.05),and the prognosis of patients in the high-quality group was better than that of patients in the low-quality group(pre-IPTW:HR=0.367,95%CI:0.275-0.491;post-IPTW:HR=0.228,95%CI:0.167-0.312).Compared with the low-quality group,the average causal effect of treatment process on in-hospital mortality was-0.026 in the high-quality group.Conclusion DR can compensate for the shortcomings of logistic or IPTW,avoid the risk of model error,and obtain for the causal effect of treatment process on in-hospital mortality.In medical practice,the utilization rate of treatment process indicators should be increased to improve patient prognosis;The study of causal effects suggests that besides the treatment process,other factors that affect in-hospital mortality cannot be ignored.