title: Real-Time Assessment of Fatigue in Patients With Multiple Sclerosis: How Does It Relate to Commonly Used Self-Report Fatigue Questionnaires?
abstract: (1) To assess real-time patterns of fatigue; (2) to assess the association between a real-time fatigue score and 3 commonly used questionnaires (Checklist Individual Strength [CIS] fatigue subscale, Modified Fatigue Impact Scale (MFIS), and Fatigue Severity Scale [FSS]); and (3) to establish factors that confound the association between the real-time fatigue score and the conventional fatigue questionnaires in patients with multiple sclerosis (MS).
  
  
  
  Cross-sectional study.
  
  
  
  MS-specialized outpatient facility.
  
  
  
  Ambulant patients with MS (N=165) experiencing severe self-reported fatigue.
  
  
  
  Not applicable.
  
  
  
  A real-time fatigue score was assessed by sending participants 4 text messages on a particular day (How fatigued do you feel at this moment?; score range, 0-10). Latent class growth mixed modeling was used to determine diurnal patterns of fatigue. Regression analyses were used to assess the association between the mean real-time fatigue score and the CIS fatigue subscale, MFIS, and FSS. Significant associations were tested for candidate confounders (eg, disease severity, work status, sleepiness).
  
  
  
  Four significantly different fatigue profiles were identified by the real-time fatigue score, namely a stable high (n=79), increasing (n=57), stable low (n=16), and decreasing (n=13). The conventional questionnaires correlated poorly (r<.300) with the real-time fatigue score. The Epworth Sleepiness Scale significantly reduced the regression coefficient between the real-time fatigue score and conventional questionnaires, ranging from 15.4% to 35%.
  
  
  
  Perceived fatigue showed 4 different diurnal patterns in patients with MS. Severity of sleepiness is an important confounder to take into account in the assessment of fatigue.
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands; Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and Rehabilitation Center De Hoogstraat, Utrecht, The Netherlands. Electronic address: m.heine@vumc.nl.
authors.forename: Martin
authors.initials: M
authors.lastname: Heine
authors.affiliation: Department of Rehabilitation Medicine, EMGO Research Institute, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Lizanne Eva
authors.initials: LE
authors.lastname: van den Akker
authors.affiliation: Department of Rehabilitation Medicine, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Lyan
authors.initials: L
authors.lastname: Blikman
authors.affiliation: Department of Health Sciences, VU University, Amsterdam, The Netherlands; Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Trynke
authors.initials: T
authors.lastname: Hoekstra
authors.affiliation: Department of Neurology, Jeroen Bosch Ziekenhuis, Den Bosch, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: van Munster
authors.affiliation: Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and Rehabilitation Center De Hoogstraat, Utrecht, The Netherlands.
authors.forename: Olaf
authors.initials: O
authors.lastname: Verschuren
authors.affiliation: Brain Center Rudolf Magnus and Center of Excellence for Rehabilitation Medicine, University Medical Center Utrecht and Rehabilitation Center De Hoogstraat, Utrecht, The Netherlands.
authors.forename: Anne
authors.initials: A
authors.lastname: Visser-Meily
authors.affiliation: Department of Rehabilitation Medicine, MOVE Research Institute, VU University Medical Center, Amsterdam, The Netherlands; Department of Neurorehabilitation, Reade Center of Rehabilitation and Rheumatology, Amsterdam, The Netherlands; Department of Physical Therapy and Human Movement Sciences, Northwestern University, Evanston, IL.
authors.forename: Gert
authors.initials: G
authors.lastname: Kwakkel
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005221:Fatigue / Q000453:epidemiology* / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000523:psychology; D010465:Perception; D026741:Physical Therapy Modalities; D012044:Regression Analysis; D015203:Reproducibility of Results; D057566:Self Report; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires / Q000592:standards*
keywords: Fatigue; Multiple Sclerosis; Rehabilitation; Surveys and questionnaires