Rasch analysis suggested three unidimensional domains for Affiliate Stigma Scale: Additional psychometric evaluation

Chih Cheng Chang, Jian An Su, Ching Shu Tsai, Cheng Fang Yen, Jiun Horng Liu, Chung-Ying Lin

Research output: Journal article publicationJournal articleAcademic researchpeer-review

61 Citations (Scopus)


Objectives To examine the psychometrics of the Affiliate Stigma Scale using rigorous psychometric analysis: classical test theory (CTT) (traditional) and Rasch analysis (modern). Differential item functioning (DIF) items were also tested using Rasch analysis. Study Design and Setting Caregivers of relatives with mental illness (n = 453; mean age: 53.29 ± 13.50 years) were recruited from southern Taiwan. Each participant filled out four questionnaires: Affiliate Stigma Scale, Rosenberg Self-Esteem Scale, Beck Anxiety Inventory, and one background information sheet. Results CTT analyses showed that the Affiliate Stigma Scale had satisfactory internal consistency (α = 0.85-0.94) and concurrent validity (Rosenberg Self-Esteem Scale: r = -0.52 to -0.46; Beck Anxiety Inventory: r = 0.27-0.34). Rasch analyses supported the unidimensionality of three domains in the Affiliate Stigma Scale and indicated four DIF items (affect domain: 1; cognitive domain: 3) across gender. Conclusion Our findings, based on rigorous statistical analysis, verified the psychometrics of the Affiliate Stigma Scale and reported its DIF items. We conclude that the three domains of the Affiliate Stigma Scale can be separately used and are suitable for measuring the affiliate stigma of caregivers of relatives with mental illness.
Original languageEnglish
Pages (from-to)674-683
Number of pages10
JournalJournal of Clinical Epidemiology
Issue number6
Publication statusPublished - 1 Jan 2015
Externally publishedYes


  • Affiliate stigma
  • Caregiver
  • Classical test theory
  • Family
  • Rasch analysis
  • Severe mental illness

ASJC Scopus subject areas

  • Epidemiology

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