title: Comparison of CKD awareness in a screening population using the Modification of Diet in Renal Disease (MDRD) study and CKD Epidemiology Collaboration (CKD-EPI) equations.
abstract: BACKGROUND
  Low awareness of chronic kidney disease (CKD) may reflect uncertainty about the accuracy or significance of a CKD diagnosis in individuals otherwise perceived to be low risk. Whether reclassification of CKD severity using the CKD Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate (GFR) modifies estimates of CKD awareness is unknown.
  
  
  METHODS
  In this cross-sectional study, we used data collected from 2000-2009 for 26,213 participants in the Kidney Early Evaluation Program (KEEP), a community-based screening program, with CKD based on GFR estimated using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation and measurement of albuminuria. We assessed CKD awareness after CKD stage was reclassified using the CKD-EPI equation.
  
  
  RESULTS
  Of 26,213 participants with CKD based on GFR estimated using the MRDR equation (eGFR(MDRD)), 23,572 (90%) also were classified with CKD based on eGFR(CKD-EPI). Based on eGFR(MDRD), 9.5% of participants overall were aware of CKD, as were 4.9%, 6.3%, 9.2%, 41.9%, and 59.2% with stages 1-5, respectively. Based on eGFR(CKD-EPI), 10.0% of participants overall were aware of CKD, as were 5.1%, 6.6%, 10.0%, 39.3%, and 59.4% with stages 1-5, respectively. Reclassification to a less advanced CKD stage using eGFR(CKD-EPI) was associated with lower odds for awareness (OR, 0.58; 95% CI, 0.50-0.67); reclassification to a more advanced stage was associated with higher odds for awareness (OR, 1.50; 95% CI, 1.05-2.13) after adjustment for confounding factors. Of participants unaware of CKD, 10.6% were reclassified as not having CKD using eGFR(CKD-EPI).
  
  
  CONCLUSIONS
  Using eGFR(CKD-EPI) led to a modest increase in overall awareness rates, primarily due to reclassification of low-risk unaware participants.
authors.affiliation: Department of Medicine, Division of Nephrology, Stanford University, Palo Alto, CA 94304, USA. mktamura@stanford.edu
authors.forename: Manjula
authors.initials: M
authors.lastname: Kurella Tamura
authors.forename: Shuchi
authors.initials: S
authors.lastname: Anand
authors.forename: Suying
authors.initials: S
authors.lastname: Li
authors.forename: Shu-Cheng
authors.initials: SC
authors.lastname: Chen
authors.forename: Adam T
authors.initials: AT
authors.lastname: Whaley-Connell
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Stevens
authors.forename: Keith C
authors.initials: KC
authors.lastname: Norris
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001364:Awareness; D003299:Cooperative Behavior; D003430:Cross-Sectional Studies; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods*; D015397:Program Evaluation / Q000379:methods*; D055815:Young Adult