Differences in morning and evening fatigue in oncology patients and their family caregivers

Abstract Purpose of the research 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. Patients and 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.