Cancer-related fatigue. Experience and outcomes

Sammanfattning: Cancer-related fatigue (CRF) is one of the most common and distressing symptoms in cancer patients and it may interfere with everyday aspects of life. Despite the recent significant increase in the literature on CRF it is nevertheless understudied, and several important questions involving experience, aetiology, assessment and interventions remain unanswered. The primary aim of this thesis was to advance the science of cancer-related fatigue and extend prior work by describing CRF over time and the relationship of fatigue to health-related quality of life in patients with uterine cancer who are receiving radiotherapy. Secondary aims were 1) to gain an understanding of the relationships between fatigue, other symptoms and selected physiological mechanisms associated with fatigue, and 2) to identify predictors of fatigue. The Conceptual Model of Symptom Management (Larson et al 1994; Dodd et al 2001) constituted the major theoretical framework for this dissertation. Both quantitative and qualitative methods have been used. In the qualitative study 15 respondents were included before data saturation was achieved. The data collection and data analysis took place in one simultaneous process in accordance with Grounded Theory. In the quantitative studies 60 patients with uterine cancer who were going to receive treatment with radiotherapy were included. Data was collected before start of radiotherapy, during radiotherapy and after completed radiotherapy mainly through self-rating instruments. The quantitative data was analysed with descriptive and non-parametric statistical methods.The results of the studies indicated that fatigue is an experience of the whole person. The patients had a low level of experienced fatigue before starting radiotherapy. The fatigue level increased significantly during the course of radiation therapy and after completed treatment. During the period of treatment, between 77 and 89% experienced fatigue. Other symptoms (loss of appetite, nausea/vomiting, diarrhoea, pain) also increased significantly during treatment and the increases were significantly correlated with general fatigue. The patients psychological distress (anxiety, depression) was low before start of treatment. Although the scores for depression had increased significantly after completed therapy, the levels were still within normal limits. The levels of coping resources, here defined as sense of coherence, were stable throughout the studies. The patients health-related quality of life was high before start of treatment. The scores for global quality of life and social function decreased significantly over time. There was a significant relationship between general fatigue and global quality of life over time when measured at baseline, after 3 weeks of therapy, and after completed therapy. There was also a significant correlation over time between general fatigue and physical function, role function and cognitive function. There was no significant correlation between general fatigue and IL-1, TNF-alpha or haemoglobin. There was a significant negative correlation between the change in IL-6 and general fatigue.The variation in the level of general fatigue after completed therapy was explained mainly by the level of experienced general fatigue at baseline. The knowledge obtained in this thesis should lead to better understanding of the cancer-related fatigue experience, including influencing variables, responses and outcomes, in women with uterine cancer who are receiving radiotherapy. Nursing interventions to help patients with CRF may include careful assessment, identification of patients at risk, and management of problems before the initiation of therapy.