title: Assessment of fatigue using the Multidimensional Fatigue Inventory in patients with major depressive disorder.
abstract: OBJECTIVE
  There are problems with the fatigue measures currently used in depressed patients. The Multidimensional Fatigue Inventory (MFI-20) covering general fatigue, physical fatigue, mental fatigue, reduced activity and reduced motivation has been widely used in patients with cancer and chronic fatigue syndrome. To address the multidimensional nature of fatigue, we examined the validity and reliability of a Chinese version of the MFI-20 in major depressive disorder (MDD).
  
  
  METHODS
  Data were derived from a randomized controlled trial of acupuncture in 137 patients with partially remitted MDD. The test-retest reliability, internal consistency, construct and concurrent validity and sensitivity to change of the MFI-20 were analyzed.
  
  
  RESULTS
  The MFI-20 was found to have good internal consistency (Cronbach's alpha=0.89) and 1-week test-retest reliability (Pearson correlation of the total score=0.73). Factor analysis showed 5 factors, but the factor structure was different from that in medical conditions. The 2 most prominent factors, explaining 46% of the total variance, were both associated with physical and mental energy but different in directions. There were adequate concurrent validity and sensitivity to change as evidenced by the significant correlations between the MFI-20 scores and depressive and anxiety symptoms, general health and quality of life.
  
  
  CONCLUSIONS
  The Chinese MFI-20 is a valid and reliable instrument for the assessment of fatigue in MDD patients with residual symptoms. The construct of fatigue in MDD seems to be different from that in medical conditions. Further studies are needed to examine the MFI-20 in MDD patients from other cultures.
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: kfchung@hkucc.hku.hk.
authors.forename: Ka-Fai
authors.initials: KF
authors.lastname: Chung
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: branadyu@hku.hk.
authors.forename: Branda Yee-Man
authors.initials: BY
authors.lastname: Yu
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: yiris@hku.hk.
authors.forename: Kam-Ping
authors.initials: KP
authors.lastname: Yung
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: yeungwfj@hku.hk.
authors.forename: Wing-Fai
authors.initials: WF
authors.lastname: Yeung
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: tommyn@hku.hk.
authors.forename: Tommy H
authors.initials: TH
authors.lastname: Ng
authors.affiliation: Department of Psychiatry, The University of Hong Kong, Hong Kong SAR, China. Electronic address: hoyy@hku.hk.
authors.forename: Fiona Yan-Yee
authors.initials: FY
authors.lastname: Ho
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People / Q000523:psychology; D003865:Major Depressive Disorder / Q000150:complications* / Q000175:diagnosis / Q000523:psychology; D005163:Factor Analysis, Statistical; D005221:Fatigue / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic