基于工具变量的丁苯酞-急性缺血性卒中的因果效应评估

Assessment of Causal Effects of Butylphthalide-acute Ischemic Stroke Based on Instrumental Variables

因果效应分析在临床统计中是一种常见的研究方法,其通常基于观察数据进行分析。然而,在使用观察数据进行因果效应分析时,常受到未观测变量的影响,从而使因果效应评估出现偏差。当无法忽略未观测变量带来的偏差或无法找到适当的代理变量来削弱这种偏差时,传统方法无法提供可靠的因果效应估计。为了解决这一问题,本文采用工具变量法,在临床统计的药效分析领域提出一种比传统方法更加准确的计算方法,将未观测变量的影响纳入误差项,以实现准确的因果效应估计。通过将观察数据中满足特定假设的变量作为工具变量,计算了丁苯酞(一种药物)对急性缺血性卒中(Acute Ischemic Stroke,AIS)患者在存在未观测变量的情况下,其3个月预后的因果效应,并评估了该因果估计量的置信区间。研究结果揭示了丁苯酞对急性缺血性卒中患者的预后恢复具有明显的积极作用。

Causal effect analysis is an important and popular method in clinical statistics,which typically conducted based on the observational data.However,the analysis based on observed data may be affected by unobserved variables,which may produce bias,leading to estimate the causal effects inaccurately.Existing methods ignore the unobserved variables or are unable to find appropriate proxy variables to weaken this bias,which fail to provide reliable estimation of the causal effects.To address this problem,this paper proposes the instrumental variable method,a more accurate computational method than traditional approaches in the realm of clinical statistic for drug efficacy analysis.This method incorporates the effect of unobserved into the error term,to estimate the accurate causal effect.Under some mild assumptions,the variables in the observational data is considered as instrumental variables.Then,the proposed method calculates the effects of butylphthalide(i.e.,a drug)on patients with acute ischemic stroke(AIS)in the presence of unobserved variables.The causal effect of monthly prognosis and the confidence interval of this causal estimator is estimated.The study results show that the butylphthalide has a significant positive effect on the prognostic recovery of patients with acute ischemic stroke.