2.1. Measurement tools
Across all phases demographic data were collected via a
short, self-completed questionnaire covering age, gender,
type of IBD and current fatigue level. Disease activity was
assessed by the Harvey–Bradshaw Index (HBI)22 for Crohn's
disease (CD) participants and the Simple Clinical Colitis
Activity Index (SCCAI) for participants with ulcerative colitis
(UC).23 Disease activity of 4 or below was classified as
remission and 5 and above was classed as active disease.
Fatigue was assessed by the Multidimensional Fatigue
Inventory (MFI), the Multidimensional Assessment of Fatigue
(MAF) and in the last two phases of the study (phase 4 and 5)
the newly developed IBD-F.
The MFI is a 20-item self-assessment instrument
designed to measure five dimensions of fatigue (physical
fatigue, mental fatigue, general fatigue, reduced activity
and motivation).24 Each dimension comprises four questions
with scores ranging from 4 to 20 per dimension, with higher
scores indicating greater fatigue. The MFI was included as,
although it has not been validated in IBD, it has been the
most frequently used scale to measure fatigue in IBD.12