title: Cognitive function and the risk of death in chronic kidney disease.
abstract: OBJECTIVE
  Cognitive impairment is a risk factor for death in dialysis patients and the general population. We sought to determine if cognitive impairment is associated with death in people with non-dialysis-dependent chronic kidney disease (CKD), and if so, whether this relationship is greater in the CKD population compared to the general population.
  
  
  METHODS
  National Health and Nutrition Examination Survey-III participants older than 60 years were asked to subtract 3 from 20 five times and to perform immediate and delayed recall of three items. A cognitive score of 0-11 was assigned based on the number of correct responses. Participants were categorized according to cognitive score (11, 9-10, 6-9, and 0-5) and CKD status. Survival analyses were conducted using Cox models.
  
  
  RESULTS
  Within the CKD subpopulation, those in the lowest cognitive score group had a twofold increased hazard of death compared to those with maximum score. Within the non-CKD subpopulation, those in the lowest cognitive score group had a 46% increased hazard of death compared to those with maximum score. However, the difference in the hazards of death in the CKD and non-CKD subpopulations with the lowest cognitive score was not significant (p = 0.99).
  
  
  CONCLUSIONS
  Low cognitive score is associated with an increased risk of death in elderly individuals with and without CKD; however, there was no interaction of CKD and low cognitive score in this analysis.
authors.affiliation: VA Healthcare System, University of Utah School of Medicine, Salt Lake City, USA. kalani.raphael@hsc.utah.edu
authors.forename: Kalani L
authors.initials: KL
authors.lastname: Raphael
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.forename: Tom
authors.initials: T
authors.lastname: Greene
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Baird
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Beddhu
mesh_terms: D000368:Aged; D003071:Cognition; D003072:Cognition Disorders / Q000150:complications*; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications* / Q000401:mortality*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012044:Regression Analysis; D012306:Risk; D012307:Risk Factors