After specifying the components of the target trial, we then try to emulate them using observational data collected and maintained by the United States Renal Data System (USRDS).
The "Researcher's Guide to the USRDS Database," available from http://www.usrds.org, describes variables, data sources, collection methods, and validation studies.
Implementing the Parametric g-Formula Using USRDS Data.
Because the hematocrit value is not available for months with zero EPO dose in the USRDS, we only simulated hematocrit when the simulated value of EPO was not zero; otherwise, we carried forward the last simulated value of hematocrit.
Table S2: Covariates Used in the g-Formula Analysis to Compare the Outcomes of Hemodialysis Patients Who Had Cardiac Disease and Were Treated with EPO: USRDS 2006-2012.
Table S3: Risks Death Only and Composite Endpoints under Low (30-33 percent), Mid (33-36 percent), and High (36-39 percent) Hematocrit Treatment Strategies, USRDS 2006-2012.