title: A rasch model to test the cross-cultural validity in the positive and negative syndrome scale (PANSS) across six geo-cultural groups.
abstract: BACKGROUND
  The objective of this study was to examine the cross-cultural differences of the PANSS across six geo-cultural regions. The specific aims are (1) to examine measurement properties of the PANSS; and (2) to examine how each of the 30 items function across geo-cultural regions.
  
  
  METHODS
  Data was obtained for 1,169 raters from 6 different regions: Eastern Asia (n = 202), India (n = 185), Northern Europe (n = 126), Russia & Ukraine (n = 197), Southern Europe (n = 162), United States (n = 297). A principle components analysis assessed unidimensionality of the subscales. Rasch rating scale analysis examined cross-cultural differences among each item of the PANSS.
  
  
  RESULTS
  Lower item values reflects items in which raters often showed less variation in the scores; higher item values reflects items with more variation in the scores. Positive Subscale: Most regions found item P5 (Excitement) to be the most difficult item to score. Items varied in severity from -0.93 [item P6. Suspiciousness/persecution (USA) to 0.69 item P4. Excitement (Eastern Asia)]. Item P3 (Hallucinatory Behavior) was the easiest item to score for all geographical regions. Negative Subscale: The most difficult item to score for all regions is N7 (Stereotyped Thinking) with India showing the most difficulty Δ = 0.69, and Northern Europe and the United States showing the least difficulty Δ = 0.21, each. The second most difficult item for raters to score was N1 (Blunted Affect) for most countries including Southern Europe (Δ = 0.30), Eastern Asia (Δ = 0.28), Russia & Ukraine (Δ = 0.22) and India (Δ = 0.10). General Psychopathology: The most difficult item for raters to score for all regions is G4 (Tension) with difficulty levels ranging from Δ = 1.38 (India) to Δ = 0.72.
  
  
  CONCLUSIONS
  There were significant differences in response to a number of items on the PANSS, possibly caused by a lack of equivalence between the original and translated versions, cultural differences among interpretation of items or scoring parameters. Knowing which items are problematic for various cultures can help guide PANSS training and make training specialized for specific geographical regions.
authors.affiliation: ProPhase, LLC, New York, NY United States of America ; Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY United States of America ; Manahttan Psychiatric Center, Wards Island, NY United States of America.
authors.forename: Anzalee
authors.initials: A
authors.lastname: Khan
authors.affiliation: ProPhase, LLC, New York, NY United States of America ; CROnos Clinical Consulting Services, Hamilton, NJ United States of America.
authors.forename: Christian
authors.initials: C
authors.lastname: Yavorsky
authors.affiliation: The PANSS Research Institute, Inc, New York, NY United States of America.
authors.forename: Stacy
authors.initials: S
authors.lastname: Liechti
authors.affiliation: ProPhase, LLC, New York, NY United States of America ; New York University, School of Medicine, New York, NY United States of America.
authors.forename: Mark
authors.initials: M
authors.lastname: Opler
authors.affiliation: ProPhase, LLC, New York, NY United States of America.
authors.forename: Brian
authors.initials: B
authors.lastname: Rothman
authors.affiliation: CROnos Clinical Consulting Services, Hamilton, NJ United States of America.
authors.forename: Guillermo
authors.initials: G
authors.lastname: DiClemente
authors.affiliation: ProPhase, LLC, New York, NY United States of America ; Pratt Institute, Brooklyn, NY United States of America.
authors.forename: Luka
authors.initials: L
authors.lastname: Lucic
authors.affiliation: ProPhase, LLC, New York, NY United States of America.
authors.forename: Sofija
authors.initials: S
authors.lastname: Jovic
authors.affiliation: Institute of Neuropsychiatry, Seiwa Hospital, Shinjuku-ku, Tokyo, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Inada
authors.affiliation: ProPhase, LLC, New York, NY United States of America ; Department of Epidemiology, Columbia University, New York, NY United States of America.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Yang