JMIR Publications

ABSTRACT

Background:

Fatigue, a common symptom in many diseases, including immune-mediated inflammatory diseases (IMID) and neurodegenerative diseases (NDD), can fluctuate within and between days. It is often measured with patient-reported outcomes (PROs) with a recall period of a week or more, which may not reflect these fluctuations adequately. Moreover, as digital technologies are offering new opportunities for the assessment of fatigue on a very granular level, reference values that are available in real time and report about fatigue at least a few times per day would be helpful for validation purposes. Such data could be collected, for example, with electronic diaries (eDiaries). However, little is known about the feasibility of such fatigue eDiaries, as well as the comparability of scores collected by such diaries with scores from established fatigue PROs.

Objective:

In this study, we evaluated the feasibility and acceptability of a fatigue eDiary administered up to 4 times per day and compared eDiary fatigue values with data obtained from an established PRO, Functional Assessment of Chronic Illness Therapy–Fatigue (FACIT-F).

Methods:

Data from 159 participants from the prospective four-week observational multi-site IDEA-FAST Feasibility Study were analysed, including participants with NDD (N=39), IMID (N=78), and healthy volunteers (N=42).

Results:

We found acceptable adherence, with 68% of expected diary entries completed across all cohorts. Data of the eDiary and the FACIT-F showed a moderate relationship (Spearman=|0.46|, P<0.001), indicating the complementary value of the eDiary data. On average, greater fatigue was reported in the evening than in the morning, indicating that time of day is an important factor to consider when administering fatigue questionnaires.

Conclusions:

In summary, this study argues in favour of the feasibility and validity of a fatigue eDiary administered up to 4 times per day over 4 weeks observation period, finding good adherence and the ability of the eDiary to capture both within and between day fluctuations in fatigue and having moderate correlation with weekly PROs of fatigue.