Kyeong Min Cha1, Young Ki Chung1, Ki Young Lim1, Jae Sung Noh1, Mison Chun2, So Yeon Hyun1, Dae Ryong Kang3, Min Jung Oh4, Nam Hee Kim5. 1. Department of Psychiatry and Behavioral Sciences, Ajou University School of Medicine, Suwon, South Korea. 2. Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea. 3. Department of Humanities and Social Medicine, Ajou University School of Medicine, Suwon, South Korea. 4. Office of Biostatistics, Department of Humanities and Social Medicine, Ajou University School of Medicine, Suwon, South Korea. 5. Department of Psychiatry and Behavioral Sciences, Ajou University School of Medicine, Suwon, South Korea. Electronic address: nadianam@gmail.com.
Abstract
BACKGROUND: Distress in cancer patients leads to poorer quality of life (QOL) and negatively impacts survival. For efficient management of a patient's disease course, the interrelationships among distress, depression, insomnia, and QOL must be understood. This study aimed to investigate whether depression and insomnia mediate the relationship between distress and QOL in cancer patients. METHODS: Cancer patients referred to a specialized psycho-oncology clinic (n=208) participated in this study. Distress, depression, insomnia, and QOL were measured with the following questionnaires: Distress Thermometer, Hospital Anxiety and Depression Scale, Insomnia Severity Index, and Functional Assessment of Cancer Therapy-General. Structural equation modeling and path analysis were performed to analyze the mediating effects of depression and insomnia on the relationship between distress and QOL. RESULTS: Distress exerted nearly equal direct (ß=-0.291, p=0.002) and indirect (mediated by depression and insomnia) (ß=-0.299, p=0.003) negative effects on QOL. Depression exhibited the largest direct negative effect on QOL. The indirect effects of distress on QOL through depression alone, through insomnia alone, and through an insomnia to depression pathway were all significant (ß=-0.122, p=0.011; ß=-0.102, p=0.002; and ß=-0.075, p<0.001, respectively). LIMITATIONS: The cross-sectional analyses limit the measurement of causal relationships between each variable. CONCLUSIONS: Depression and insomnia, both individually and as part of an interrelated pathway, partially mediate the relationship between distress and QOL. Appropriate interventions to alleviate insomnia and depression may mitigate the negative impacts of distress on QOL in cancer patients.
BACKGROUND: Distress in cancerpatients leads to poorer quality of life (QOL) and negatively impacts survival. For efficient management of a patient's disease course, the interrelationships among distress, depression, insomnia, and QOL must be understood. This study aimed to investigate whether depression and insomnia mediate the relationship between distress and QOL in cancerpatients. METHODS:Cancerpatients referred to a specialized psycho-oncology clinic (n=208) participated in this study. Distress, depression, insomnia, and QOL were measured with the following questionnaires: Distress Thermometer, Hospital Anxiety and Depression Scale, Insomnia Severity Index, and Functional Assessment of Cancer Therapy-General. Structural equation modeling and path analysis were performed to analyze the mediating effects of depression and insomnia on the relationship between distress and QOL. RESULTS: Distress exerted nearly equal direct (ß=-0.291, p=0.002) and indirect (mediated by depression and insomnia) (ß=-0.299, p=0.003) negative effects on QOL. Depression exhibited the largest direct negative effect on QOL. The indirect effects of distress on QOL through depression alone, through insomnia alone, and through an insomnia to depression pathway were all significant (ß=-0.122, p=0.011; ß=-0.102, p=0.002; and ß=-0.075, p<0.001, respectively). LIMITATIONS: The cross-sectional analyses limit the measurement of causal relationships between each variable. CONCLUSIONS:Depression and insomnia, both individually and as part of an interrelated pathway, partially mediate the relationship between distress and QOL. Appropriate interventions to alleviate insomnia and depression may mitigate the negative impacts of distress on QOL in cancerpatients.