Determining risk factors of continuous renal replacement treatment after emergency surgery for type A acute aortic dissection: statistical issues

This letter to the editor has made several comments regarding possible statistical issues in recent article by Wang et al. determining the risk factors of continuous renal replacement treatment after emergency surgery for type A acute aortic dissection, which is published in Journal of Cardiothoracic Surgery. 2020; 15(1):100. Our comments were involved in the issues of using the propensity score matched cohorts to adjust the covariates that can potentially confound the primary outcomes, process of establishing multivariate model and application of Kaplan-Meier curve analysis in this retrospective study. We would like to remind readers to pay special attention to these issues and invite the authors to comment on these.