A review of the content and psychometric properties of cancer-related fatigue (CRF) measures used to assess fatigue in intervention studies

Purpose Cancer-related fatigue (CRF) is a common and debilitating consequence of cancer and its treatment. Numerous supportive care interventions have been developed to alleviate CRF; however, the diversity of outcome measures used to assess CRF limits comparability of findings. We aimed to evaluate the content and psychometric properties of measures used to assess CRF in interventions targeting fatigue, to inform the selection of suitable measures in future research. Methods Included measures were identified from a systematic review of interventions targeting CRF. General characteristics of each measure were extracted, and item content was assessed against domains specified by the National Comprehensive Cancer Network (NCCN) definition of CRF. Psychometric properties were evaluated against COnsensus-based Standards for the selection of heath Measurement INstruments (COSMIN) criteria. Results Of 54 measures identified, 25 met inclusion criteria. Seventeen were fatigue-specific and eight a fatigue subscale or single item within a broader measure. Only 14 (56%) were specifically developed for cancer populations. Content coverage according to the NCCN CRF definition ranged from 0 to 75%. Evidence for fulfilment of COSMIN criteria in cancer populations ranged from 0 to 93%, with only five measures meeting > 70% of the COSMIN criteria. Conclusion The Piper Fatigue Scale-Revised had good content coverage, but did not comprehensively address COSMIN criteria. The EORTC-FA12 and FACIT/FACT-F had excellent psychometric properties, with each capturing different aspects of fatigue. Ultimately, the choice of CRF measure should be guided by the research question and the CRF domains most relevant to the particular research context.