Existing instruments that measure the impact of cancer-related fatigue on health-related quality of life do not usually incorporate the attitudes, beliefs and perspectives of patients. This study aimed to develop an instrument to measure the impact of cancer-related fatigue on the health-related quality of life of cancer patients.
Items were generated from a literature review, focus groups of cancer patients and meetings with oncologists. Potential items were administered to cancer patients to facilitate item reduction, which was based on clinimetric and psychometric analyses and qualitative criteria. A preliminary assessment of feasibility, reliability and validity of the retained items was performed.
An initial pool of 75 items was administered to 238 cancer patients. Fifty items were eliminated after statistical analysis and 13 in response to expert opinion, resulting in a provisional instrument with 12 items in 3 dimensions. These displayed acceptable internal consistency (Cronbach's alpha, 0.78–0.92) and their overall score was associated with fatigue intensity, extent of disease, intention of treatment and need of caregivers.
The newly developed questionnaire, which measures the impact of cancer-related fatigue on oncology patients, has shown satisfactory feasibility, reliability and validity.