Longitudinal development of fatigue after treatment for childhood cancer: a national cohort study

Background: Fatigue is a distressing and prevalent long-term sequela of treatment for childhood cancer, and there is a need for longitudinal studies to investigate the development of fatigue over time. The objective of this study was to calculate growth-curves for the longitudinal development of fatigue after treatment for childhood cancer, and to investigate the effects of biopsychosocial predictors. Materials and methods: Participants were recruited from a patient monitoring program and data extracted from medical records. Parent-proxy and self-report versions of PedsQLTM Multidimensional Fatigue Scale were used to repeatedly assess fatigue up to 5 years after the end of treatment for childhood cancer. Fatigue was assessed 2440 times for 761 participants (median:3) with proxy-reports (age 2–8 years) and 2657 times for 990 participants with self-reports (above 8 years) (median:2). Mixed models were used to establish growth-curves and to analyze the effect of predictors separately for participants with solid tumors (ST), hemato-oncological malignancies and central nervous system-tumors (CNS). Results: CNS-tumors were associated with more cognitive fatigue than ST at the end of treatment, for both proxy-reports (−11.30, p