Changes in and predictors of severity of fatigue in women with breast cancer: A longitudinal study

Background: Fatigue is the most common symptom experienced by cancer patients. However, longitudinal studies of changes in the severity and predictors of fatigue are limited. Objectives: The purposes of this study were to evaluate changes in fatigue severity in women with breast cancer prior to and for twelve months after surgery. Factors that affected the severity and the trajectory of fatigue were identified. Design, settings, participants: This observational prospective study approached 334 women who were scheduled for breast cancer surgery in a medical center located in northern Taiwan. Among the 334 women, 239 met the inclusion/exclusion criteria. The final sample size used for the data analysis was 200. Methods: Fatigue, depressive symptom, and symptom distress were evaluated in women prior to and at 1, 2, 3, 4, 5, 6, 8, 10, and 12 months after surgery for breast cancer. Hierarchical linear modeling (HLM) was applied where level-1 data consisted of repeated observations of study variables within each subject and level-2 data consisted of static characteristics of individual subject. Results: The fatigue levels ranged from 1.92 to 3.09. Changes in fatigue severity demonstrated a quadratic trajectory that increased and reached the peak at the second month after the surgery, followed by a gradual decreased. After adjusting for the effect of receipt of chemotherapy, symptom distress, and depressive symptom, the quadratic change pattern for fatigue became imperceptible. Women who had a partial mastectomy (P=0.028), had a higher educational level (P=0.048), were married (P=0.043), and had poorer functional performance at diagnosis (P=0.043) had higher levels of fatigue. Conclusions: Patients who underwent surgery for breast cancer reported mild to moderate levels of fatigue over a period of 12 months. Fatigue levels fluctuated with patients' level of depressive symptoms, symptom distress, and receipt of chemotherapy.