title: Subgroups of chemotherapy patients with distinct morning and evening fatigue trajectories.
abstract: OBJECTIVE
  Purposes of this study were to identify subgroups of patients with distinct trajectories for morning and evening fatigue, evaluate for differences in demographic and clinical characteristics among these subgroups, and compare and contrast the predictors of subgroup membership for morning and evening fatigue.
  
  
  METHODS
  Outpatients with breast, gastrointestinal, gynecological, or lung cancer (n = 582) completed questionnaires, a total of six times over two cycles of chemotherapy (CTX). Morning and evening fatigue severity were evaluated using the Lee Fatigue Scale. Latent profile analysis (LPA) was used to identify distinct subgroups.
  
  
  RESULTS
  Three latent classes were identified for morning fatigue (i.e., low (31.8 %), high (51.4 %), and very high (16.8 %)) and for evening fatigue (i.e., moderate (20.0 %), high (21.8 %), and very high (58.2 %)). Most of the disease and treatment characteristics did not distinguish among the morning and evening fatigue classes. Compared to the low class, patients in the high and very high morning fatigue classes were younger, had a lower functional status, and higher level of comorbidity. Compared to the moderate class, patients in the very high evening fatigue class were younger, more likely to be female, had child care responsibilities, had a lower functional status, and a higher level of comorbidity.
  
  
  CONCLUSIONS
  LPA allows for the identification of risk factors for more severe fatigue. Since an overlap was not observed across the morning and evening fatigue classes and unique predictors for morning and evening fatigue were identified, these findings suggest that morning and evening fatigue may have distinct underlying mechanisms.
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA. kord.kober@ucsf.edu.|Department of Physiological Nursing, University of California, 2 Koret Way - N631, San Francisco, CA, 94143-0610, USA. kord.kober@ucsf.edu.
authors.forename: Kord M
authors.identifier: http://orcid.org/0000-0001-9732-3321
authors.initials: KM
authors.lastname: Kober
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Cooper
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Paul
authors.affiliation: School of Medicine, University of California, San Francisco, California, USA.
authors.forename: Laura B
authors.initials: LB
authors.lastname: Dunn
authors.affiliation: School of Medicine, University of California, San Francisco, California, USA.
authors.forename: Jon D
authors.initials: JD
authors.lastname: Levine
authors.affiliation: College of Nursing, New York University, New York, New York, USA.
authors.forename: Fay
authors.initials: F
authors.lastname: Wright
authors.affiliation: College of Nursing, New York University, New York, New York, USA.
authors.forename: Marilyn J
authors.initials: MJ
authors.lastname: Hammer
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Judy
authors.initials: J
authors.lastname: Mastick
authors.affiliation: School of Medicine, University of California, San Francisco, California, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Venook
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.|Institute for Human Genetics, University of California, San Francisco, California, USA.
authors.forename: Bradley E
authors.initials: BE
authors.lastname: Aouizerat
authors.affiliation: School of Nursing, University of California, San Francisco, California, USA.
authors.forename: Christine
authors.initials: C
authors.lastname: Miaskowski
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects*; D002940:Circadian Rhythm; D005221:Fatigue / Q000209:etiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D011795:Surveys and Questionnaires
chemical_list: D000970:Antineoplastic Agents
keywords: Cancer; Chemotherapy; Diurnal variations; Evening fatigue; Fatigue; Latent class analysis; Latent profile analysis; Morning fatigue