Austin Peter C, Mamdani Muhammad M
Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
Stat Med. 2006 Jun 30;25(12):2084-106. doi: 10.1002/sim.2328.
There is an increasing interest in the use of propensity score methods to estimate causal effects in observational studies. However, recent systematic reviews have demonstrated that propensity score methods are inconsistently used and frequently poorly applied in the medical literature. In this study, we compared the following propensity score methods for estimating the reduction in all-cause mortality due to statin therapy for patients hospitalized with acute myocardial infarction: propensity-score matching, stratification using the propensity score, covariate adjustment using the propensity score, and weighting using the propensity score. We used propensity score methods to estimate both adjusted treated effects and the absolute and relative risk reduction in all-cause mortality. We also examined the use of statistical hypothesis testing, standardized differences, box plots, non-parametric density estimates, and quantile-quantile plots to assess residual confounding that remained after stratification or matching on the propensity score. Estimates of the absolute reduction in 3-year mortality ranged from 2.1 to 4.5 per cent, while estimates of the relative risk reduction ranged from 13.3 to 17.0 per cent. Adjusted estimates of the reduction in the odds of 3-year death varied from 15 to 24 per cent across the different propensity score methods.
在观察性研究中，使用倾向评分方法来估计因果效应的兴趣日益浓厚。然而，最近的系统评价表明，倾向评分方法在医学文献中的使用并不一致，且经常应用不当。在本研究中，我们比较了以下几种倾向评分方法，以估计急性心肌梗死住院患者接受他汀类药物治疗后全因死亡率的降低情况：倾向评分匹配、使用倾向评分进行分层、使用倾向评分进行协变量调整以及使用倾向评分进行加权。我们使用倾向评分方法来估计调整后的治疗效果以及全因死亡率的绝对和相对风险降低情况。我们还研究了使用统计假设检验、标准化差异、箱线图、非参数密度估计和分位数-分位数图来评估在倾向评分分层或匹配后仍存在的残余混杂因素。3年死亡率绝对降低的估计值范围为2.1%至4.5%，而相对风险降低的估计值范围为13.3%至17.0%。不同倾向评分方法对3年死亡几率降低的调整估计值在15%至24%之间变化。
