title: The kidney disease quality of life cognitive function subscale and cognitive performance in maintenance hemodialysis patients.
abstract: BACKGROUND
  Cognitive impairment is common but often undiagnosed in patients with end-stage renal disease, in part reflecting limited validated and easily administered tools to assess cognitive function in dialysis patients. Accordingly, we assessed the utility of the Kidney Disease Quality of Life Cognitive Function (KDQOL-CF) scale in comparison to an extensive neuropsychological battery, building on a prior assessment of this potential cognitive screen.
  
  
  METHODS
  Cross-sectional cohort.
  
  
  METHODS
  Maintenance hemodialysis patients at 6 Boston area dialysis units were administered an extensive neurocognitive battery and the KDQOL-CF at the beginning of a hemodialysis session.
  
  
  METHODS
  KDQOL-CF score, depression symptom burden, and demographic and clinical characteristics.
  
  
  RESULTS
  Neurocognitive performance classified into executive function and memory domains, determined using principal components analysis.
  
  
  METHODS
  Univariate and multivariable linear regression models adjusting for age, sex, race, and end-stage renal disease cause were used to evaluate the association between KDQOL-CF score and cognitive performance, and test metrics were determined for a KDQOL-CF cutoff score of 60 or less from a maximum score of 100.
  
  
  RESULTS
  For 168 prevalent hemodialysis patients, KDQOL-CF score was 76 ± 19 and 40 (24%) had scores of 60 or less, consistent with self-identified worse cognitive performance. There was no significant correlation between KDQOL-CF score and either memory (P = 0.2 and P = 0.3) or executive function (P = 0.1 and P = 0.4) in univariate and multivariable models, respectively. There was a strong correlation between higher KDQOL-CF score and fewer depression symptoms (P < 0.001). Sensitivity of the KDQOL-CF was poor (range, 0.28-0.36), with modest specificity (range, 0.77-0.81) for identifying worse executive function and memory.
  
  
  CONCLUSIONS
  Cross-sectional study, modest population size, and abbreviated gold-standard cognitive battery.
  
  
  CONCLUSIONS
  The KDQOL-CF is a poor determinant of neurocognitive performance in hemodialysis patients, with limited sensitivity. To assess cognitive impairment in hemodialysis patients, better screening tests are essential.
authors.affiliation: University of California San Diego School of Medicine, San Diego, CA, USA.
authors.forename: Eric P
authors.initials: EP
authors.lastname: Sorensen
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sarnak
authors.forename: Hocine
authors.initials: H
authors.lastname: Tighiouart
authors.forename: Tammy
authors.initials: T
authors.lastname: Scott
authors.forename: Lena M
authors.initials: LM
authors.lastname: Giang
authors.forename: Bethany
authors.initials: B
authors.lastname: Kirkpatrick
authors.forename: Kristina
authors.initials: K
authors.lastname: Lou
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Weiner
mesh_terms: D017677:Age Distribution; D000368:Aged; D000704:Analysis of Variance; D003072:Cognition Disorders / Q000175:diagnosis* / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000523:psychology* / Q000628:therapy*; D016014:Linear Models; D008134:Long-Term Care; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D011788:Quality of Life; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods / Q000523:psychology*; D018570:Risk Assessment; D017678:Sex Distribution; D016896:Treatment Outcome