BFI

The Brief Fatigue Inventory (BFI) is a 9-item self-report measure developed at MD Anderson Cancer Center to assess the severity and impact of cancer-related fatigue. Three items rate fatigue severity (current, usual, worst in last 24 hours) on a 0–10 numeric scale, and six items measure fatigue interference with daily life (general activity, mood, walking, work, relations, enjoyment of life). The global fatigue score is the mean of all nine items. The BFI is used in psychedelic end-of-life research as a secondary endpoint, as cancer-related fatigue often coexists with depression and existential distress. Improvements in fatigue following psilocybin-assisted therapy may reflect both direct effects and indirect benefits from improved mood and existential well-being. The BFI takes approximately 5 minutes to complete and has been validated in multiple cancer populations and languages.