Clinically relevant fatigue in cancer outpatients: the Edinburgh Cancer Centre symptom study

Background: Fatigue is associated with cancer and its treatment but we know little about how many and which patients suffer fatigue of clinical severity. We aimed to determine the prevalence of clinically relevant fatigue (CRF) and its associations in outpatients with various cancer diagnoses. Patients and methods: A survey of outpatients with colorectal, breast, gynaecological, gentourinary, sarcoma, melanoma and miscellaneous tumours at a regional cancer Centre. Patients completed the European Organisation for Research and Treatment of Cancer (EORTC) fatigue subscale and the Hospital Anxiety and Depression Scale (HADS). These self-report data were linked to demographic and clinical variables. Data were available on 2867 outpatients. Results: The prevalence of CRF (EORTC fatigue subscale >= 40) was 32% (95% confidence interval 31-34%). The variables independently associated with CRF were primary cancer site, having disease present, type of cancer treatment and emotional distress (total HADS score >= 5). Emotional distress had the strongest association with fatigue but half the cases of CRF were not distressed. Conclusion: CRF is common in cancer outpatients and is associated with type of disease and treatment, as well as with emotional distress. The association between CRF and emotional distress is strong but they are not equivalent conditions.