title: Subjective sleep efficiency of hemodialysis patients.
abstract: BACKGROUND
  Sleep disturbances have a major influence on quality of life. A commonly used measure of sleep disturbances is sleep efficiency. The purpose of this study was to investigate the prevalence of decreased subjective sleep efficiency in hemodialysis patients. An additional goal was to identify clinical, dialysis or laboratory parameters that are independently associated with decreased sleep efficiency.
  
  
  METHODS
  Adult stable hemodialysis patients (n = 112) filled out a sleep questionnaire during a three day investigation period. In addition, healthy control subjects (n = 44) filled out the same questionnaire. From this questionnaire sleep efficiency (ratio of total sleep time to time spent in bed) was derived as a measure for sleep disturbances in this population. Laboratory, demographic and dialysis data were collected during the investigation period. For statistical analysis linear regression models were used.
  
  
  RESULTS
  Median subjective sleep efficiency in hemodialysis patients was 80%, which was significantly less compared to the median subjective sleep efficiency of control subjects of 88% (p pound 0.05). Approximately 40% of the patients used sleep medication. However, less than 20% of them indicated improved sleep behavior when using these drugs. Elevated levels of phosphate and urea correlated independently with impaired sleep efficiency. Hemoglobin levels between 10 and 12 g/dl were associated with better sleep efficiency.
  
  
  CONCLUSIONS
  In conclusion, decreased sleep efficiency was frequently reported in hemodialysis patients and can be associated with biochemical parameters. Hemoglobin, phosphate and urea levels can affect subjective sleep efficiency.
authors.affiliation: Department of Clinical Pharmacy, Meander MC, Amersfoort, The Netherlands. bcp.koch@meandermc.nl
authors.forename: B C P
authors.initials: BC
authors.lastname: Koch
authors.forename: J E
authors.initials: JE
authors.lastname: Nagtegaal
authors.forename: E C
authors.initials: EC
authors.lastname: Hagen
authors.forename: W Th
authors.initials: WT
authors.lastname: van Dorp
authors.forename: J B S
authors.initials: JB
authors.lastname: Boringa
authors.forename: G A
authors.initials: GA
authors.lastname: Kerkhof
authors.forename: P M
authors.initials: PM
authors.lastname: Ter Wee
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy; D008297:Male; D011379:Prognosis; D006435:Renal Dialysis / Q000009:adverse effects*; D012189:Retrospective Studies; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000209:etiology / Q000503:physiopathology*; D011795:Surveys and Questionnaires