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

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.

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.

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.

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