Survivorship and Patients Perspective
A. Mayer1,*, N. Stadtbäumer1,*, S. Kreissl2, H. Müller2, H. Görgen2, P. Borchmann2
1 RWTH Aachen University, Aachen, Germany, 2 German Hodgkin Study Group (GHSG), University Hospital of Cologne, Germany
* Shared first authorship.
Background: Cancer-related fatigue (CRF) is among the most distressing symptoms reported by cancer survivors. It often persists for years after treatment, compromising the quality of life (QoL) of survivors. There is some evidence for a correlation between CRF and functional health (FH) based on cross-sectional data. The aim of this study is to investigate the directional effects and the complex interplay between CRF and FH in survivors of Hodgkin lymphoma (HL) using longitudinal data.
Methods: Data of N = 3595 survivors from year 1 to year 5 after the end of treatment of the fifth study generation (HD13–15) of the German Hodgkin Study Group (GHSG) was analysed. Bivariate latent curve models with structured residuals (LCM-SR, Figure 1) were utilized to simultaneously model how the reciprocal relation between the two -constructs unfolds over time across and within individuals. CRF and FH were both measured with the EORTC QLQ-C30. Assessed FH domains were physical, cognitive, emotional, social and role functioning.
Results: The LCM-SRs had an adequate model fit (Chi-Square 315.61–417.46, df = 50, p < .001, RMSEA = .04-.05, CFI = .98-.99, TLI = .98-.99). On the between-person level, CRF and each FH domain were strongly negative correlated (range r = –.77 to r = –.87), indicating that persons with higher FH scores have lower CRF scores on average. On the within-person level, earlier CRF scores negatively and significantly predicted subsequent scores of each FH domain (small effects, range i = –.04 to i = –.11). In the same way, earlier scores of each FH domain predicted subsequent scores of CRF (small effects, range k = –.04 to k = –.13). Social and role functioning were in a balanced reciprocal relation with CRF, meaning that time-specific within-person improvements of social and role functioning reduced subsequent CRF and vice-versa. Time-specific within-person effects of physical, cognitive and emotional functioning on subsequent CRF scores were stronger than vice-versa, indicating that an improvement of physical, cognitive and emotional functioning reduces CRF more than the other way around.
Conclusion: Our analysis reveals a complex reciprocal relationship between CRF and FH. To fully depict the complex interplay, distinct between- and within-person effects had to be considered. A better understanding of these associations could be used to develop targeted interventions that minimize the risk of CRF and persistently reduced QoL for HL survivors.