A CAUSAL MODEL FOR FATIGUE IN VIETNAMESE PERSONS WITH LUNG CANCER RECEIVING CHEMOTHERAPY

Abstract

This cross-sectional study aimed to examine the causal model explaining fatigue in lung cancer patients during chemotherapy. The study was conducted in six oncology centers throughout the North of Vietnam. The hypothesized model was constructed based on the Piper’s Integrative Fatigue Model and the review of literature. A convenience sample of 246 patients was interviewed by self-administered questionnaires, which were Functional Assessment of Chronic Illness Therapy‐Fatigue Scale (FACT-F), Insomnia Severity Index (ISI), Cancer Dyspnea Scale (CDS), Manchester Cough in Lung Cancer Scale (MCLCS), Depression Stress Anxiety Scale 21-Anxiety subscale (DASS-21-An), and International Physical Activity Questionnaire-short form. Cronbach’s alpha coefficients of FACT-F, ISI, CDS, MCLCS, and DASS-21-An found in this study were 0.93, 0.90, 0.86, 0.86, and 0.77, respectively. Nutrition status of patients was assessed by Nutrition Risk Index based on information in patients’ medical records. Structural equation modeling was used to examine the hypothesized model in this study. It was found that the final model (consisted of insomnia, dyspnea, cough, anxiety, stage of disease, physical activity, and nutrition status) explained 42.9% fatigue variance (χ2 = 51.556, df = 38, p = 0.070; χ2/ df = 1.357; GFI = 0.963; AGFI = 0.937; CFI = 0.974; RSMEA = 0.038). There were the interplays among dyspnea, cough, insomnia, and anxiety in determining fatigue. Among such factors, dyspnea had the largest total effect on fatigue (β = 0.397, p < 0.01), followed by cough (β = 0.343, p < 0.01), insomnia (β = 0.318, p < 0.01) and anxiety (β = 0.115, p < 0.05). Stage of disease influenced fatigue by its direct effect (β = 0.154, p < 0.05) and indirect effect via physical activity (β = 0.025, p < 0.05). Physical activity and nutrition status, however, had only direct and negative effects on fatigue (β = -.148 and -0.156, p < 0.01, respectively). In conclusion, the model fits well to explain fatigue in lung cancer patients during chemotherapy. Vietnamese nurses should include insomnia in their fatigue control programs. In comparison to cough, dyspnea might be a better intervening factor to manage fatigue. Interventions focusing on physical activity, nutritional status, and anxiety may promise positive, although not too large, outcomes in reducing fatigue. Importantly, the interplay among insomnia, dyspnea, anxiety, and cough suggests that the development of comprehensive symptom management programs, which focus on those symptoms, could be a promising approach to control fatigue for Vietnamese nurses.