Department of Health Psychology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Department of Psychology, University of British Columbia, Vancouver, BC, Canada.
Psychooncology. 2018 Mar;27(3):831-837. doi: 10.1002/pon.4574. Epub 2017 Nov 23.
Fatigue is a distressing symptom many cancer patients experience even after completion of treatment. Although theory and empirical evidence indicate that negative cognitions perpetuate fatigue after completion of treatment, insight into how this process unfolds in daily life is limited. This study used an intensive longitudinal design to investigate the reciprocal relationship between catastrophizing and fatigue in daily life and whether affective and behavioral processes mediate these relationships.
Post-treatment colorectal cancer patients (n = 101) completed daily diaries (14 days, 3 times daily) regarding their fatigue, catastrophizing, positive and negative affect, and physical activity. Multilevel modeling was applied to investigate within-person associations within days.
Analyses revealed a positive reciprocal relationship between fatigue and catastrophizing throughout the day. That is, high levels of catastrophizing were associated with increases in fatigue within patients. In turn, but to a lesser extent, high levels of fatigue predicted increases in catastrophizing at the next assessment. Low positive affect and high negative affect mediated the effect of catastrophizing on increases in fatigue. Only negative affect mediated the reverse relationship. Physical activity did not mediate either relationship.
This study provides evidence for a mutually reinforcing relationship between catastrophizing and fatigue in daily life, which might explain the perpetuation of fatigue after completion of cancer treatment. Fatigue-specific cognitive behavior therapy could be improved by educating patients about this daily reciprocal relationship, train them to quickly replace catastrophizing thoughts in daily life, and help them to cope with affective changes induced by fatigue.
疲劳是许多癌症患者在治疗完成后仍会经历的一种令人痛苦的症状。尽管理论和实证证据表明，消极认知会使治疗完成后疲劳持续存在，但对这一过程在日常生活中如何展开的了解有限。本研究采用密集纵向设计，调查日常生活中灾难化思维与疲劳之间的相互关系，以及情感和行为过程是否介导这些关系。
治疗后结直肠癌患者（n=101）每天完成 3 次（共 14 天）关于疲劳、灾难化思维、积极和消极情绪以及身体活动的日记。多水平模型用于在日内研究个体内的关联。
分析显示，疲劳和灾难化思维在一天中呈正相关的循环关系。也就是说，较高水平的灾难化思维与患者内疲劳的增加有关。反过来，疲劳程度较低与下一次评估时灾难化思维的增加呈正相关，但程度较低。低积极情绪和高消极情绪中介了灾难化思维对疲劳增加的影响。只有消极情绪中介了反向关系。身体活动不能中介这两种关系。
本研究为日常生活中灾难化思维和疲劳之间的相互增强关系提供了证据，这可能解释了癌症治疗完成后疲劳的持续存在。通过教育患者了解这种日常的相互关系，可以改进针对疲劳的特定认知行为疗法，训练他们在日常生活中迅速替换灾难化思维，并帮助他们应对疲劳引起的情感变化。
