Validation of erythropoietin use data on Medicare's End-Stage Renal Disease Medical Evidence Report.

Data from Medicare's End-Stage Renal Disease Medical Evidence Report (Form 2728) suggest that underuse of erythropoiesis-stimulating agents (ESAs) may be contributing to anemia in predialysis patients. However, the data quality of Form 2728 is not known. ESA prescription records were confirmed in Department of Veterans Affairs (VA) data sets and/or ESA claims in Medicare files and compared with data collected on Form 2728 among 8,033 veterans who initiated dialysis in 2000 and 2001 and were eligible for both VA and Medicare coverage in the 12 months preceding dialysis initiation. Among the cohort, predialysis ESA use was found in 4% (n = 323) more veterans by VA/Medicare data sets (n = 2,810) than by Form 2728 (n = 2,487). With the use of VA/Medicare data sets (gold standard), the accuracy of Form 2728 for predialysis ESA use was sensitivity 57.0%, specificity 83.1%, positive predictive value 64.5%, negative predictive value 78.2%, and kappa coefficient 0.41. Sensitivity for reported predialysis ESA use on Form 2728 was lowest among veterans who were female and nonwhite, of low socioeconomic status, and with anemia or other comorbid illnesses. The poor sensitivity and specificity of predialysis ESA use data on Form 2728 raise concerns about the validity of previous reports and study findings. Investigators should recognize these shortcomings and the introduction of possible bias in future research and reports.