Dialysis Cognitive Impairment and 7-Year Mortality in Dialysis Patients Konstadina Griva, PhD, 1,2 Jan Stygall, MSc, 2 Matthew Hankins, MSc, 3 Andrew Davenport, FRCP, 4 Michael Harrison, FRCP, 2 and Stanton P. Newman, PhD 2 Background: Although dementia has predicted mortality in large dialysis cohorts, little is known about the relationship between less pronounced cognitive deficits and mortality in patients with end-stage renal disease. This study assessed whether cognitive impairment without dementia was an independent predictor of 7-year survival in dialysis patients after controlling for other risk factors. Study Design: Prospective single-cohort study. Setting & Participants: 145 prevalent dialysis patients from 2 units in London, UK, were followed up for 64.3  27.4 months and censored at the time of change to a different treatment. Predictors: Cognitive impairment, defined as performance 1 standard deviation less than normative values on 2 or more cognitive tests within a neurocognitive battery assessing attention/concentration, memory, and psychomotor function domains. Depression, quality-of-life, and clinical measures also were obtained. Outcomes & Measurements: All-cause mortality was the primary outcome. Cox proportional hazard models were used to assess the contribution of demographics and clinical and psychological measures and cognitive impairment to mortality. Results: 98 (67.6%) patients were cognitively impaired at baseline. At follow-up, 56 (38.6%) patients had died, 29 of cardiac causes. Unadjusted Kaplan-Meier analysis showed higher mortality in cogni- tively impaired patients, in whom 7-year survival was 49% versus 83.2% in those with no cognitive impairment (P  0.001). Mortality risk associated with cognitive impairment remained significant in adjusted analysis controlling for sociodemographic, clinical, and psychological factors (adjusted HR, 2.53; 95% CI, 1.03-6.22; P = 0.04). Limitations: Small sample size and number of events. Conclusions: Cognitive impairment is an independent predictor of mortality in dialysis patients. Although the implications of early recognition and treatment of cognitive impairment for clinical outcomes are unclear, these results suggest that patient management protocols should attempt to ensure prevention of cognitive decline in addition to managing coexisting medical conditions. Am J Kidney Dis 56:693-703. © 2010 by the National Kidney Foundation, Inc. INDEX WORDS: Cognition; mortality; dialysis; impairment. Editorial, p. 615 A ll-cause and cardiovascular mortality rates for dialysis patients are high despite con- tinual improvement in dialysis technology. This may be a consequence of the increased number of elderly patients and patients with concurrent systemic diseases admitted to dialysis pro- grams. 1 Determinants of mortality in patients with end-stage renal disease (ESRD) treated us- ing hemodialysis include older age and comorbid illnesses, such as diabetes mellitus, inflamma- tion, and nutritional status. 2-5 Psychosocial fac- tors, such as depression, 6,7 social support, 8 and quality of life (QoL), also have been associated with mortality in dialysis patients. 9-14 Cognitive dysfunction is a well-recognized additional complication of ESRD, with recent studies showing that deficits are apparent early in the progression of kidney disease. 15-17 Dialysis patients have presented with impairments in cog- nitive abilities, such as poor memory, motor and From the 1 Department of Psychology, National University of Singapore, Singapore; 2 Unit of Behavioural Medicine, Uni- versity College London and Health Services Research Group, City University London; 3 Institute of Psychiatry, Kings College London; and 4 Department of Nephrology, Royal Free and Middlesex Hospital, London, UK. Received January 16, 2010. Accepted in revised form July 1, 2010. Originally published online as doi:10.1053/j.ajkd. 2010.07.003 on August 27, 2010. Address correspondence to Stanton P. Newman, PhD, Health Services Research Group, City University London, Northampton Square, London EC1V 0HB, UK. E-mail: s.newman@ucl.ac.uk © 2010 by the National Kidney Foundation, Inc. 0272-6386/10/5604-0013$36.00/0 doi:10.1053/j.ajkd.2010.07.003 American Journal of Kidney Diseases, Vol 56, No 4 (October), 2010: pp 693-703 693