title: Mortality Prediction in the Oldest Old with Five Different Equations to Estimate Glomerular Filtration Rate: The Health and Anemia Population-based Study.
abstract: BACKGROUND
  Kidney function declines considerably with age, but little is known about its clinical significance in the oldest-old.
  
  
  OBJECTIVE
  To study the association between reduced glomerular filtration rate (GFR) estimated according to five equations with mortality in the oldest-old.
  
  
  METHODS
  Prospective population-based study.
  
  
  METHODS
  Municipality of Biella, Piedmont, Italy.
  
  
  METHODS
  700 subjects aged 85 and older participating in the "Health and Anemia" Study in 2007-2008.
  
  
  METHODS
  GFR was estimated using five creatinine-based equations: the Cockcroft-Gault (C-G), Modification of Diet in Renal Disease (MDRD), MAYO Clinic, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Berlin Initiative Study-1 (BIS-1). Survival analysis was used to study mortality in subjects with reduced eGFR (<60 mL/min/1.73 m(2)) compared to subjects with eGFR ≥ 60 mL/min/1.73 m(2).
  
  
  RESULTS
  Prevalence of reduced GFR was 90.7% with the C-G, 48.1% with MDRD, 23.3% with MAYO, 53.6% with CKD-EPI and 84.4% with BIS-1. After adjustment for confounders, two-year mortality was significantly increased in subjects with reduced eGFR using BIS-1 and C-G equations (adjusted HRs: 2.88 and 3.30, respectively). Five-year mortality was significantly increased in subjects with eGFR <60 mL/min/1.73 m(2) using MAYO, CKD-EPI and, in a graduated fashion in reduced eGFR categories, MDRD. After 5 years, oldest old with an eGFR <30 mL/min/1.73 m(2) showed a significantly higher risk of death whichever equation was used (adjusted HRs between 2.04 and 2.70).
  
  
  CONCLUSIONS
  In the oldest old, prevalence of reduced eGFR varies noticeably depending on the equation used. In this population, risk of mortality was significantly higher for reduced GFR estimated with the BIS-1 and C-G equations over the short term. Though after five years the MDRD appeared on the whole a more consistent predictor, differences in mortality prediction among equations over the long term were less apparent. Noteworthy, subjects with a severely reduced GFR were consistently at higher risk of death regardless of the equation used to estimate GFR.
authors: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors: Sara
authors: S
authors: Mandelli
authors: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors: Emma
authors: E
authors: Riva
authors: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors: Mauro
authors: M
authors: Tettamanti
authors: Laboratory of Analysis, Ospedale degli Infermi, Biella, Italy.
authors: Paolo
authors: P
authors: Detoma
authors: County Cancer Registry, Local Health Authority, Biella, Italy.
authors: Adriano
authors: A
authors: Giacomin
authors: Laboratory of Geriatric Neuropsychiatry, IRCCS-Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy.
authors: Ugo
authors: U
authors: Lucca
mesh_terms: D000369:Aged, 80 and over; D000740:Anemia / Q000401:mortality* / Q000503:physiopathology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D011237:Predictive Value of Tests; D015995:Prevalence; D051436:Renal Insufficiency, Chronic / Q000401:mortality* / Q000503:physiopathology*; D012307:Risk Factors