Context: Fatigue is the most common symptom in oncology patients during chemotherapy. Little is known about the predictors of interindividual variability in initial levels and trajectories of morning fatigue severity in these patients.

Objectives: An evaluation was done to determine which demographic, clinical, and symptom characteristics were associated with initial levels as well as the trajectories of morning fatigue and to compare findings with our companion paper on evening fatigue.

Methods: A sample of outpatients with breast, gastrointestinal, gynecological, and lung cancer (n = 586) completed demographic and symptom questionnaires a total of six times over two cycles of chemotherapy. Fatigue severity was evaluated using the Lee Fatigue Scale. Hierarchical linear modeling was used to answer the study objectives.

Results: A large amount of interindividual variability was found in the morning fatigue trajectories. A piecewise model fit the data best. Patients with higher body mass index, who did not exercise regularly, with a lower functional status, and who had higher levels of state anxiety, sleep disturbance, and depressive symptoms reported higher levels of morning fatigue at enrollment. Variations in the trajectories of morning fatigue were predicted by the patients' ethnicity and younger age.

Conclusion: The modifiable risk factors that were associated with only morning fatigue were body mass index, exercise, and state anxiety. Modifiable risk factors that were associated with both morning and evening fatigue included functional status, depressive symptoms, and sleep disturbance. Using this information, clinicians can identify patients at higher risk for more severe morning fatigue and evening fatigue, provide individualized patient education, and tailor interventions to address the modifiable risk factors.