Quality of Life Differences In an African American and Caucasian Sample of Chronic Illness Patients: Assessment of Differential Item Functioning

  • Scott M. Debb
  • David L. Blitz
  • Seunh W. Choi


The value of a health care intervention is judged by its impact on the quantity and quality of life (QOL) of an individual (Cella & Bonomi, 1996). When analyzing QOL data, results from the general population are often as- sumed to be equally representative of various subpopulations; however, establishing measurement invariance across different populations (e.g., racial and ethnic groups) is crucial for score interpretability. In this study, ordinal logistic regression (following Zumbo, 1999) was used to examine differential item functioning (DIF) in an African American and Caucasian sample of 898 cancer and chronic illness patients that had been administered a QOL questionnaire for use with chronic illness sufferers. Results indicated that significant differences in response patterns were present between the two groups. This has which have clinical implications pertaining to psychological assessment, conceptualization and intervention. 


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