title: Predicting the risk of end-stage renal disease in the population-based setting: a retrospective case-control study.
abstract: BACKGROUND
  Previous studies of predictors of end-stage renal disease (ESRD) have limitations: (1) some focused on patients with clinically recognized chronic kidney disease (CKD); (2) others identified population-based patients who developed ESRD, but lacked earlier baseline clinical measures to predict ESRD. Our study was designed to address these limitations and to identify the strength and precision of characteristics that might predict ESRD pragmatically for decision-makers--as measured by the onset of renal replacement therapy (RRT).
  
  
  METHODS
  We conducted a population-based, retrospective case-control study of patients who developed ESRD and started RRT. We conducted the study in a health maintenance organization, Kaiser Permanente Northwest (KPNW). The case-control study was nested within the adult population of KPNW members who were enrolled during 1999, the baseline period. Cases and their matched controls were identified from January 2000 through December 2004. We evaluated baseline clinical characteristics measured during routine care by calculating the adjusted odds ratios and their 95% confidence intervals after controlling for matching characteristics: age, sex, and year.
  
  
  RESULTS
  The rate of RRT in the cohort from which we sampled was 58 per 100,000 person-years (95% CI, 53 to 64). After excluding patients with missing data, we analyzed 350 cases and 2,114 controls. We identified the following characteristics that predicted ESRD with odds ratios ≥ 2.0: eGFR<60 mL/min/1.73 m(2) (OR = 20.5; 95% CI, 11.2 to 37.3), positive test for proteinuria (OR = 5.0; 95% CI, 3.5 to 7.1), hypertension (OR = 4.5; 95% CI, 2.5 to 8.0), gout/positive test for uric acid (OR = 2.5; 95% CI, 1.8 to 3.5), peripheral vascular disease (OR = 2.2; 95% CI, 1.4 to 3.6), congestive heart failure (OR = 2.1; 95% CI, 1.4 to 3.3), and diabetes (OR = 2.1; 95% CI, 1.5 to 2.9).
  
  
  CONCLUSIONS
  The clinical characteristics needed to predict ESRD--for example, to develop a population-based, prognostic risk score--were often documented during routine care years before patients developed ESRD and required RRT.
authors.affiliation: The Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon, USA. eric.s.johnson@kpchr.org
authors.forename: Eric S
authors.initials: ES
authors.lastname: Johnson
authors.forename: David H
authors.initials: DH
authors.lastname: Smith
authors.forename: Micah L
authors.initials: ML
authors.lastname: Thorp
authors.forename: Xiuhai
authors.initials: X
authors.lastname: Yang
authors.forename: Juhaeri
authors.initials: J
authors.lastname: Juhaeri
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D048909:Diabetes Complications / Q000150:complications; D005260:Female; D006333:Heart Failure / Q000150:complications; D006801:Humans; D006973:Hypertension / Q000150:complications; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000150:complications; D011507:Proteinuria / Q000150:complications; D017582:Renal Replacement Therapy; D012189:Retrospective Studies; D012307:Risk Factors