UBC Theses and Dissertations
Gender differential item functioning effects on various item response formats of the CES-D Gelin, Michaela Nicole
The present study investigated potentially biased scale items on the Center for Epidemiologic Studies Depression (CES-D) scale in a sample of 600 community-dwelling adults between the ages of 17 and 87 years. The mean age was 46 years for males (N=310) and 42 years for females (N=290). The 20-item CES-D was scored using two binary methods (presence and persistence) and one ordinal method. Gender differential item functioning (DIF) was explored using Zumbo's (1999) ordinal logistic regression method with corresponding logistic regression effect size estimator with all three scoring methods. After statistically matching males and females on the underlying ability, gender DIF was found with the CES-D item crying for the ordinal and presence methods of scoring. The persistence scoring method identified two DEF items (effort and hopeful), however, this scoring method was of limited use due to low response rates on some items. Overall, the results indicate that the scoring method has an effect on DEF; thus DEF is a property of the item, scoring method, and purpose of the instrument.
Item Citations and Data