title: Functional Dependence and Mortality in the International Dialysis Outcomes and Practice Patterns Study (DOPPS).
abstract: BACKGROUND
  Patients receiving long-term dialysis have among the highest mortality and hospitalization rates. In the nonrenal literature, functional dependence is recognized as a contributor to subsequent disability, recurrent hospitalization, and increased mortality. A higher burden of functional dependence with progressive worsening of kidney function has been observed in several studies, suggesting that functional dependence may contribute to both morbidity and mortality in dialysis patients.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  7,226 hemodialysis patients from 12 countries in the DOPPS (Dialysis Outcomes and Practice Patterns Study) phase 4 (2009-2011) with self-reported data for functional status.
  
  
  METHODS
  Patients' ability to perform 13 basic and instrumental activities of daily living was summarized to create an overall functional status score (range, 1.25 [most dependent] to 13 [functionally independent]).
  
  
  RESULTS
  Cox regression was used to estimate the association between functional status and all-cause mortality, adjusting for several demographic and clinical risk factors for mortality. Median follow-up was 17.2 months.
  
  
  RESULTS
  The proportion of patients who could perform each activity of daily living task without assistance ranged from 97% (eating) to 47% (doing housework). 36% of patients could perform all 13 tasks without assistance (functional status = 13), and 14% of patients had high functional dependence (functional status < 8). Functionally independent patients were younger and had many indicators of better health status, including higher quality of life. Compared with functionally independent patients, the adjusted HR for mortality was 2.37 (95% CI, 1.92-2.94) for patients with functional status < 8.
  
  
  CONCLUSIONS
  Possible nonresponse bias and residual confounding.
  
  
  CONCLUSIONS
  We found a high burden of functional dependence across all age groups and across all DOPPS countries. When adjusting for several known mortality risk factors, including age, access type, cachexia, and multimorbidity, functional dependence was a strong consistent predictor of mortality.
authors.affiliation: Division of Nephrology, University Health Network, Toronto, Canada.
authors.forename: S Vanita
authors.initials: SV
authors.lastname: Jassal
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI.
authors.forename: Angelo
authors.initials: A
authors.lastname: Karaboyas
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI; University of Michigan, Ann Arbor, MI.
authors.forename: Leah A
authors.initials: LA
authors.lastname: Comment
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Bieber
authors.affiliation: Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, MI; Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI; Department of Urology, Medical School, University of Michigan, Ann Arbor, MI.
authors.forename: Hal
authors.initials: H
authors.lastname: Morgenstern
authors.affiliation: University of Michigan, Ann Arbor, MI.
authors.forename: Ananda
authors.initials: A
authors.lastname: Sen
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI; University of Michigan, Ann Arbor, MI.
authors.forename: Brenda W
authors.initials: BW
authors.lastname: Gillespie
authors.affiliation: University Hospital Infanta Leonor, Madrid, Spain.
authors.forename: Patricia
authors.initials: P
authors.lastname: De Sequera
authors.affiliation: Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand; Department of Renal Medicine, Counties Manukau Health, Auckland, New Zealand; Baxter Healthcare (Asia Pacific), Shanghai, People's Republic of China.
authors.forename: Mark R
authors.initials: MR
authors.lastname: Marshall
authors.affiliation: Kyoto University, Sakyo-ku, Kyoto, Japan; Center for Innovative Research in Community and Clinical Excellence, Fukushima Medical University, Fukushima, Japan.
authors.forename: Shunichi
authors.initials: S
authors.lastname: Fukuhara
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI; University of Michigan, Ann Arbor, MI.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Robinson
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Pisoni
authors.affiliation: Arbor Research Collaborative for Health, Ann Arbor, MI; Vanderbilt University Medical Center, Nashville, TN. Electronic address: francesca.tentori@arborresearch.org.
authors.forename: Francesca
authors.initials: F
authors.lastname: Tentori
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D038622:Internationality; D008297:Male; D008875:Middle Aged; D009026:Mortality / Q000639:trends; D011446:Prospective Studies; D006435:Renal Dialysis / Q000401:mortality* / Q000639:trends; D016896:Treatment Outcome
keywords: Chronic kidney disease (CKD); Dialysis Outcomes and Practice Patterns Study (DOPPS); activity of daily living (ADL); dialysis; end-stage renal disease (ESRD); functional dependence; functional status; hospitalization; independence; morbidity; mortality; physical activity; quality of life (QoL)