title: The Chinese Version of the Gotland Male Depression Scale (GMDS): Mokken scaling.
abstract: OBJECTIVE
  Invariant item ordering (IIO) is defined as the extent to which items have the same order for each respondent who completes a scale. IIO is crucial for establishing a scale hierarchy that is replicable across samples; however, no research has demonstrated IIO in the Gotland Male Depression Scale (GMDS). The aim of this study was to determine if an IIO hierarchy of depressive symptoms existed in a clinical sample of men who completed the GMDS.
  
  
  METHODS
  A convenience sample of 231 men (age: mean (SD) = 46.1 (11.0) yrs) who visited a men's health polyclinic in Taiwan and completed the GMDS. Mokken scale analysis was conducted to evaluate the psychometric properties of the GMDS.
  
  
  RESULTS
  All items on the GMDS formed a strong uni-dimensional scale (H=0.592). Except for item #9 (alcohol/drug abuse, or hyperactivity), IIO was found for the remaining 12 items (H(T)=0.366). These symptoms reflected the following hierarchy: positive family history (#13), complaining (#12), anxiety (#8), loss of vitality (#10), depressed mood (#11), indecisiveness (#6), aggression (#2), irritability (#5), stress (#1), burn-out (#3), fatigue (#4), and sleep problems (#7).
  
  
  CONCLUSIONS
  The GMDS is a psychometrically sound measure of depressive symptoms in Taiwanese male outpatients. The GMDS has both cumulative and hierarchical properties.
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan.
authors.forename: Chin-Pang
authors.initials: CP
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan; School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Chun-Lin
authors.initials: CL
authors.lastname: Chu
authors.affiliation: Department of Urology, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan; School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan; School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Kun-Hao
authors.initials: KH
authors.lastname: Jiang
authors.affiliation: Department of Traditional Chinese Medicine, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan; School of Medicine, Chang Gung University, Taoyuan, Taiwan.
authors.forename: Jiun-Liang
authors.initials: JL
authors.lastname: Chen
authors.affiliation: Department of Psychiatry, Chang Gung Memorial Hospital, Linkou branch, Taiwan; Men's Health Center, Chang Gung Memorial Hospital, Taoyuan branch, Taiwan; School of Medicine, Chang Gung University, Taoyuan, Taiwan. Electronic address: psycychen@yahoo.com.tw.
authors.forename: Ching-Yen
authors.initials: CY
authors.lastname: Chen
mesh_terms: D000328:Adult; D001007:Anxiety; D044466:Asian People; D003863:Depression / Q000175:diagnosis* / Q000523:psychology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data*; D011594:Psychometrics / Q000379:methods*; D011795:Surveys and Questionnaires; D063189:Symptom Assessment / Q000379:methods* / Q000523:psychology; D013624:Taiwan; D014177:Translations
keywords: Gotland Male Depression Scale; Item ordering; Item response theory; Men; Mokken scale analysis