title: Fatigue, vitality, sleep, and neurocognitive functioning in adult survivors of childhood cancer: a report from the Childhood Cancer Survivor Study.
abstract: BACKGROUND
  Long-term survivors of childhood cancer are at risk for fatigue, sleep problems, and neurocognitive impairment, although the association between these outcomes has not been previously examined.
  
  
  METHODS
  Outcomes were evaluated in 1426 survivors from the Childhood Cancer Survivor Study using a validated Neurocognitive Questionnaire. Relative risks for neurocognitive impairment were calculated using demographic and treatment factors, and survivors' report on the Functional Assessment of Chronic Illness Therapy-Fatigue, the Short Form-36 Vitality Scale, the Pittsburgh Sleep Quality Index, and the Epworth Sleepiness Scale.
  
  
  RESULTS
  Neurocognitive impairment was identified in >20% of survivors, using sibling-based norms for comparison. Multivariate logistic regression models revealed that fatigue (risk ratio [RR], 1.34; 95% confidence interval [CI], 1.13-1.59), daytime sleepiness (RR, 1.68; 95% CI, 1.55-1.83), poor sleep quality (RR, 1.23; 95% CI, 1.01-1.49), and decreased vitality (RR, 1.75; 95% CI 1.33-2.30) were all associated with impaired task efficiency. Likewise, fatigue (RR, 1.77; 95% CI, 1.23-2.55), sleepiness (RR, 1.38; 95% CI, 1.14-1.67), and decreased vitality (RR, 3.08; 95% CI, 1.98-4.79) were predictive of emotional regulation problems. Diminished organization was associated with increased sleepiness (RR, 1.80; 95% CI, 1.31-2.48) and decreased vitality (RR, 1.90; 95% CI, 1.37-2.63). Impaired memory was associated with poor sleep quality (RR, 1.45; 95% CI, 1.19-1.76), increased sleepiness (RR, 2.05; 95% CI, 1.63-2.58), and decreased vitality (RR, 2.01; 95% CI, 1.42-2.86). The impact of fatigue, sleepiness, sleep quality, and vitality on neurocognitive outcomes was independent of the effects of cranial radiation therapy, steroids and antimetabolite chemotherapy, sex, and current age.
  
  
  CONCLUSIONS
  Neurocognitive function in long-term survivors of childhood cancer appears particularly vulnerable to the effects of fatigue and sleep disruption. These findings suggest sleep hygiene should be emphasized among survivors, as it may provide an additional mechanism for intervention to improve neurocognitive outcomes.
authors.affiliation: Department of Psychology, St. Jude Children's Research Hospital, Memphis, Tennessee.
authors.forename: Nancy R
authors.initials: NR
authors.lastname: Clanton
authors.forename: James L
authors.initials: JL
authors.lastname: Klosky
authors.forename: Chenghong
authors.initials: C
authors.lastname: Li
authors.forename: Neelam
authors.initials: N
authors.lastname: Jain
authors.forename: Deo Kumar
authors.initials: DK
authors.lastname: Srivastava
authors.forename: Daniel
authors.initials: D
authors.lastname: Mulrooney
authors.forename: Lonnie
authors.initials: L
authors.lastname: Zeltzer
authors.forename: Marilyn
authors.initials: M
authors.lastname: Stovall
authors.forename: Leslie L
authors.initials: LL
authors.lastname: Robison
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Krull
mesh_terms: D000328:Adult; D060825:Cognitive Dysfunction / Q000150:complications*; D005221:Fatigue / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000453:epidemiology*; D011788:Quality of Life; D012307:Risk Factors; D035781:Siblings; D012893:Sleep Wake Disorders / Q000150:complications*; D011795:Surveys and Questionnaires; D017741:Survivors; D055815:Young Adult