The USRDS: what you need to know about what it can and can't tell us about ESRD.

This article summarizes the administrative structure underlying the Unites States Renal Data System (USRDS); summarizes incidence, prevalence, patient characteristics, and treatment modalities; and describes data regarding clinical indicators and preventive care, hospitalization, survival, and costs. The USRDS recently instituted a comprehensive assessment system to characterize the transition to the new Centers for Medicare & Medicaid Services Prospective Payment System, which bundles into a single payment several integral components of dialysis care. This challenging initiative will be an important component of future USRDS Annual Data Reports. The main strengths of the USRDS are its size and representativeness, nearly complete inclusion of the US end-stage renal disease population, and linkage to Medicare claims. Limitations include lack of continuous validation of its methods, lack of complete comorbidity and laboratory data at registration, an initial survival bias, and lack of accuracy of cause-of-death reporting.