Background: Linkage to the US Renal Data System (USRDS) registry commonly is used to identify end-stage renal disease (ESRD) cases, or kidney failure treated with dialysis or transplantation, but it underestimates the total burden of kidney failure. This study validates a kidney failure definition that includes both kidney failure treated and not treated by dialysis or transplantation. It compares kidney failure risk factors and outcomes using this broader definition with USRDS-identified ESRD risk factors and outcomes.
Study design: Diagnostic test study with stratified random sampling of hospitalizations for chart review.
Setting & participants: Atherosclerosis Risk in Communities Study (n=11,530; chart review, n=546).
Index test: USRDS-identified ESRD; treated or untreated kidney failure defined by USRDS-identified ESRD or International Classification of Diseases, Ninth or Tenth Revision, Clinical Modification (ICD-9-CM/ICD-10-CM) code for hospitalization or death.
Reference test: For ESRD, determination of permanent dialysis therapy or transplantation; for kidney failure, determination of permanent dialysis therapy, transplantation, or estimated glomerular filtration rate < 15 mL/min/1.73 m(2).
Results: During 13 years' median follow-up, 508 kidney failure cases were identified, including 173 (34.1%) from the USRDS registry. ESRD and kidney failure incidence were 1.23 and 3.66 cases per 1,000 person-years in the overall population and 1.35 and 6.59 cases per 1,000 person-years among participants older than 70 years, respectively. Other risk-factor associations were similar between ESRD and kidney failure, except diabetes and albuminuria, which were stronger for ESRD. Survivals at 1 and 5 years were 74.0% and 24.0% for ESRD and 59.8% and 31.6% for kidney failure, respectively. Sensitivity and specificity were 88.0% and 97.3% comparing the kidney failure ICD-9-CM/ICD-10-CM code algorithm to chart review; for USRDS-identified ESRD, sensitivity and specificity were 94.9% and 100.0%.
Limitations: Some medical charts were incomplete.
Conclusions: A kidney failure definition including treated and untreated disease identifies more cases than linkage to the USRDS registry alone, particularly among older adults. Future studies might consider reporting both USRDS-identified ESRD and a more inclusive kidney failure definition.
Keywords: Atherosclerosis Risk in Communities (ARIC) Study; End-stage renal disease (ESRD); US Renal Data System (USRDS); chronic kidney disease (CKD); chronic kidney failure; hospitalization; renal replacement therapy (RRT); sensitivity and specificity; untreated renal failure; validation studies.
Copyright © 2015 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.