title: Sleep/Wake patterns of individuals with advanced cancer measured by ambulatory polysomnography.
abstract: OBJECTIVE
  Sleep/wake disturbances are prevalent in patients with advanced cancer, but 24-hour polysomnography (PSG) examinations of these patterns have not been undertaken. The purpose of this study was to describe these sleep/wake patterns using continuous PSG and to explore relationships with selected demographic and clinical variables.
  
  
  METHODS
  The sample included patients with advanced cancer (solid tumors); those with neurologic disorders or psychosis, substance abuse, or brain metastasis were excluded. The final sample included 114 participants with a mean age of 51.1 years (+/- 9.1 years). Participants underwent continuous, ambulatory PSG for 42 hours in their home environments. Standard PSG measures were calculated. Analysis included data from 2 nights and the intervening day. Descriptive statistics were used to summarize sleep/wake parameters of the average of the 2 nights and the intervening day. Nonparametric analyses were used to detect differences and relationships among the variables.
  
  
  RESULTS
  Compared with normative data, participants had reduced quantity and quality of nocturnal sleep and episodes of sleep scattered throughout the day. Increased daytime sleep was negatively associated with several key parameters of nocturnal sleep quantity and quality. Women, whites, and those who were married/partnered and had more education had better nocturnal sleep. Cancer type and selected medications may be risk factors for disturbed sleep and waking.
  
  
  CONCLUSIONS
  Participants experienced severe difficulty with "state maintenance", or the ability to maintain both the sleep and waking states. Research designed to identify the etiology of these problems is needed to develop effective interventions.
authors.affiliation: Nell Hodgson Woodruff School of Nursing, Emory University, 1520 Clifton Road, Atlanta, GA 30322-4207, USA. kpark04@emory.edu
authors.forename: Kathy P
authors.initials: KP
authors.lastname: Parker
authors.forename: Donald L
authors.initials: DL
authors.lastname: Bliwise
authors.forename: Maria
authors.initials: M
authors.lastname: Ribeiro
authors.forename: Sanjay R
authors.initials: SR
authors.lastname: Jain
authors.forename: Catherine I
authors.initials: CI
authors.lastname: Vena
authors.forename: Mary Kay
authors.initials: MK
authors.lastname: Kohles-Baker
authors.forename: Andre
authors.initials: A
authors.lastname: Rogatko
authors.forename: Zhiheng
authors.initials: Z
authors.lastname: Xu
authors.forename: Wayne B
authors.initials: WB
authors.lastname: Harris
mesh_terms: D000368:Aged; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D009369:Neoplasms / Q000150:complications*; D017286:Polysomnography; D011788:Quality of Life; D012894:Sleep Stages; D012893:Sleep Wake Disorders / Q000209:etiology*