title: Tracking daily fatigue fluctuations in multiple sclerosis: ecological momentary assessment provides unique insights.
abstract: Studies investigating the prevalence, cause, and consequence of multiple sclerosis (MS) fatigue typically use single measures that implicitly assume symptom-stability over time, neglecting information about if, when, and why severity fluctuates. We aimed to examine the extent of moment-to-moment and day-to-day variability in fatigue in relapsing-remitting MS and healthy individuals, and identify daily life determinants of fluctuations. Over 4 weekdays, 76 participants (38 relapsing-remitting MS; 38 controls) recruited from multiple sites provided real-time self-reports six times daily (n = 1661 observations analyzed) measuring fatigue severity, stressors, mood, and physical exertion, and daily self-reports of sleep quality. Fatigue fluctuations were evident in both groups. Fatigue was highest in relapsing-remitting MS, typically peaking in late-afternoon. In controls, fatigue started lower and increased steadily until bedtime. Real-time stressors and negative mood were associated with increased fatigue, and positive mood with decreased fatigue in both groups. Increased fatigue was related to physical exertion in relapsing-remitting MS, and poorer sleep quality in controls. In relapsing-remitting MS, fatigue fluctuates substantially over time. Many daily life determinants of fluctuations are similar in relapsing-remitting MS and healthy individuals (stressors, mood) but physical exertion seems more relevant in relapsing-remitting MS and sleep quality most relevant in healthy individuals.
authors.affiliation: Aberdeen Health Psychology Group, Institute of Applied Health Sciences, University of Aberdeen, 2nd Floor Health Sciences Building, Foresterhill Campus, Aberdeen, AB25 2ZD, UK. daniel.powell@abdn.ac.uk.|Psychology, Faculty of Social and Human Sciences, University of Southampton, Southampton, SO17 1BJ, UK. daniel.powell@abdn.ac.uk.
authors.forename: Daniel J H
authors.initials: DJH
authors.lastname: Powell
authors.affiliation: Psychology, Faculty of Social and Human Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
authors.forename: Christina
authors.initials: C
authors.lastname: Liossi
authors.affiliation: Psychology, Faculty of Social and Human Sciences, University of Southampton, Southampton, SO17 1BJ, UK.|Max Planck Institute of Empirical Aesthetics, 60322, Frankfurt am Main, Germany.
authors.forename: Wolff
authors.initials: W
authors.lastname: Schlotz
authors.affiliation: Psychology, Faculty of Social and Human Sciences, University of Southampton, Southampton, SO17 1BJ, UK.|Health Psychology Section, Psychology Department, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, SE1 9RT, UK.
authors.forename: Rona
authors.initials: R
authors.lastname: Moss-Morris
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D000368:Aged; D016022:Case-Control Studies; D000072860:Ecological Momentary Assessment; D005221:Fatigue / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications*; D005082:Physical Exertion; D057566:Self Report; D012890:Sleep; D013997:Time Factors; D055815:Young Adult
keywords: Affect; Ambulatory assessment; Ecological momentary assessment; Fatigue; Multiple sclerosis; Psychological stress