Validation of the cause of renal failure of patients in the Medicare end-stage renal disease program.

Studies addressing the epidemiological issues of end-stage renal disease (ESRD) and the implications for health resource allocations are valuable, especially because the Medicare ESRD program is expected to continue growing during the next decade. Studies on trends in the causes of renal failure have benefited from Medicare's extensive data files on ESRD patients. However, no studies have been published that validate the cause of renal failure field in the Medicare files. The primary disease causing renal failure for over 10,000 New York State patients in the Medicare ESRD program was compared with their hospital discharge diagnoses. Of these patients, 8,730 (83%) had a known cause of renal failure in the Health Care Financing Administration (HCFA) data files. Eighty-nine percent of these patients' primary cause of renal failure was matched with the same major hospital diagnostic code. Patients with diabetes and glomerulonephritis had the highest overall match rates (96% to 97%). Patients with polycystic kidney disease and causes of renal failure other than the four major causes had the lowest match rates (75% to 76%), but these match rates increased to 84% to 87% for patients hospitalized more than five times. Some differences in match rate by age and race were found. These findings suggest that HCFA data on the causes of renal failure of ESRD patients are reasonably accurate and can be used successfully to study a variety of issues related to the diseases leading to chronic renal failure.