title: Differences in morning and evening fatigue in oncology patients and their family caregivers.
abstract: OBJECTIVE
  To identify distinct latent classes of individuals based on ratings of morning and evening fatigue; evaluate for differences in phenotypic characteristics, as well as symptom and quality of life scores, among these latent classes; and evaluate for an overlap in morning and evening fatigue class membership.
  
  
  METHODS
  In a sample of 167 oncology outpatients and 85 of their FCs, growth mixture modeling was used to identify distinct latent classes based on ratings of morning and evening fatigue obtained before, during, and after radiation therapy. Analyses of variance and Chi Square analyses were used to evaluate for differences among the morning and evening fatigue latent classes.
  
  
  RESULTS
  Three distinct latent classes for morning fatigue were identified. Participants in the High Morning Fatigue class (47%) were younger and had lower functional status. Three distinct latent classes for evening fatigue were identified. Participants in the High Evening Fatigue class (61%) were younger, more likely to be female, more likely to have children at home, and more likely to be a FC. Only 10.3% of participants were classified in both the Very Low Morning and Low Evening Fatigue classes and 41.3% were classified in both the High Morning and High Evening Fatigue classes.
  
  
  CONCLUSIONS
  Different characteristics were associated with morning and evening fatigue, which suggests that morning and evening fatigue may be distinct but related symptoms. Additional research is needed to elucidate the mechanisms that may underlie diurnal variability in fatigue.
authors.affiliation: School of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Anand
authors.initials: A
authors.lastname: Dhruva
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Aouizerat
authors.forename: Bruce
authors.initials: B
authors.lastname: Cooper
authors.forename: Steven M
authors.initials: SM
authors.lastname: Paul
authors.forename: Marylin
authors.initials: M
authors.lastname: Dodd
authors.forename: Claudia
authors.initials: C
authors.lastname: West
authors.forename: William
authors.initials: W
authors.lastname: Wara
authors.forename: Kathryn
authors.initials: K
authors.lastname: Lee
authors.forename: Laura B
authors.initials: LB
authors.lastname: Dunn
authors.forename: Dale J
authors.initials: DJ
authors.lastname: Langford
authors.forename: John D
authors.initials: JD
authors.lastname: Merriman
authors.forename: Christina
authors.initials: C
authors.lastname: Baggott
authors.forename: Janine
authors.initials: J
authors.lastname: Cataldo
authors.forename: Christine
authors.initials: C
authors.lastname: Ritchie
authors.forename: Kord
authors.initials: K
authors.lastname: Kober
authors.forename: Heather
authors.initials: H
authors.lastname: Leutwyler
authors.forename: Christine
authors.initials: C
authors.lastname: Miaskowski
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000553:Ambulatory Care / Q000379:methods*; D000554:Ambulatory Care Facilities / Q000458:organization & administration; D000704:Analysis of Variance; D002173:Cancer Care Facilities; D017028:Caregivers; D016009:Chi-Square Distribution; D002940:Circadian Rhythm; D005221:Fatigue / Q000209:etiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000175:diagnosis / Q000532:radiotherapy*; D018570:Risk Assessment; D012720:Severity of Illness Index; D012737:Sex Factors
keywords: Cancer treatment; Diurnal variability; Evening fatigue; Fatigue; Growth mixture modeling; Latent class analysis; Morning fatigue; Radiation therapy