摘要倾向评分加权是利用倾向评分值对每个观察单位进行加权调整.由于倾向评分将许多协变量综合为一个变量,因此通过倾向评分加权可以使各混杂变量在两组人群中的分布趋于一致.根据调整后标准人群的不同分为两种加权方法:逆处理概率加权法(IPTW)和标准化死亡比加权法(SMRW).本文实例分析表明,用IPTW和SMRW加权调整后处理组和对照组妇女各混杂变量的分布均趋于一致,两种方法调整后的效应估计基本相同.本文介绍倾向评分加权法的基本原理、具体方法,并结合实例探讨了其在流行病学中的应用.

abstractsIn this article,we presented the rationale and calculation procedures of a propensity score weighting method,with its application in epidemiological studies.The rationale for propensity score weighting method is similar to those for traditional standardization methods.Propensity score is used to estimate the weight for each individual.As the propensity score serves the function of observed covariates,the propensity score weighting can balance the distribution of the observed covariates between the comparison groups.There are two weighting methods according to the target standard populations:the Inverse probability of treatment weighting(IPTW)and the Standardized mortality ratio weighting(SMRW).Results of the example show that the distribution of the covariates tended to be consistent after weighting,and the IPTW and SMRW methods showed similar effect estimates.Propensity score weighting method can effectively balance the distribution of the confounding factors between the compared groups in non-randomized controlled trials.