Causal relationships among factors associated with cancer-related fatigue.
OBJECTIVE
This study was conducted to develop and verify a comprehensive model, which illustrates the dynamic causal relationships between fatigue and its associated factors in cancer patients.


METHODS
The subjects were 110 in- or out-patients with various types of cancer being treated at a University Hospital, Incheon, South Korea. The comprehensive model consists of physical distress, sleep-related, physiologic, psychological distress, physical performance, and exercise factors.


RESULTS
Psychological distress had a significant direct effect on physical distress, and 81% of the variance in physical distress was explained by psychological distress. While psychological distress showed to have a significant total effect (the sum of direct effects of psychological distress and indirect effects through its relationship with physical distress) on fatigue, it was not found to have a significant direct effect on fatigue. Only exercise had a significant direct effect on fatigue and 70% of fatigue variance was explained by exercise alone. All remaining factors were not found to have significant direct effects on fatigue.


CONCLUSIONS
The hypothetical model was well suited to explain cancer-related fatigue. Our result indicates that psychological distress should be relieved in combination with a strategy to reduce physical distress in order to obtain better outcomes with respect to cancer-related fatigue. Only exercise had a significant direct effect on fatigue. In terms of the nursing implications, the proposed model can help oncology nurses better understand cancer-related fatigue and assess presence of correctable correlates. This model can be a future framework when developing intervention strategies for cancer-related fatigue.
Seo
YoungMin
Y
Department of Nursing, Inha University Hospital, SinHeung Dong 7-206, Incheon 400-711, Republic of Korea.
Oh
HyunSoo
H
Seo
WhaSook
W
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D015984:Causality; D016009:Chi-Square Distribution; D003430:Cross-Sectional Studies; D015444:Exercise; D005221:Fatigue / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications*; D009859:Oncology Nursing; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D007319:Sleep Initiation and Maintenance Disorders / Q000150:complications; D013315:Stress, Psychological / Q000150:complications