Fatigue screening in breast cancer patients: identifying likely cases of cancer-related fatigue

Abstract

Objective: For clinical and research purposes, efficient identification of cases of cancer-related fatigue (CRF) is important, as CRF can be persistent and interfere with usual functioning. While various fatigue-screening instruments are available, no brief screening indices have been developed using formally diagnosed CRF cases as the criterion.

Methods: Breast cancer patients (n = 385) completed a fatigue diagnostic interview and self-report fatigue measures (Profile of Mood States-fatigue subscale, Fatigue Symptom Inventory, and SF-36 vitality subscale), after initial adjuvant therapy (post-treatment (post-Tx) 1 assessment), after completion of radiotherapy for women receiving chemotherapy + radiotherapy (post-Tx 2 assessment), and 6 months after completion of all adjuvant therapy (6-month post-Tx assessment). CRF cases were identified using specific diagnostic criteria. ROC analyses identified screening indices, which could accurately identify CRF cases after initial adjuvant therapy. Screening indices were cross-validated using post-Tx 2 and 6-month follow-up assessment data.

Results: A total of 104 women (27%) met CRF criteria after initial adjuvant therapy. Six two-item screening indices were identified. For all indices, area under the curve exceeded 0.80, sensitivity exceeded 0.80, and specificity exceeded 0.57. Cross-validation suggested that, except for the index based on SF-36, all the indices continued to accurately identify CRF cases at the post-Tx 2 and 6-month post-Tx assessments. Overall, a two-item composite index based on Fatigue Symptom Inventory 'most severity' and 'work interference' items performed best.

Conclusions: Breast cancer patients and survivors meeting CRF diagnostic criteria can be accurately identified using brief screening indices derived from common self-report fatigue measures.