Differential item responses on CES-D inventory: A comparison of elderly Hispanics and non-Hispanic Whites in the United States and item usage by elderly Hispanics across time

Abstract

Objectives: This study examines the differential item functioning (DIF) on both the standard 20-item scale and 10-item and 12-item subsets of the Center for Epidemiological Studies Depression (CES-D) inventory. Method: Two elderly groups in the United States are compared: one composed of Hispanics and the other of non-Hispanic Whites. We also compare item use among the elderly Hispanics over time. Survey data was analyzed from participants (N = 4499) in the Established Populations for Epidemiologic Studies of the Elderly (EPESE) with complete data on the CES-D. Partial correlation analysis was applied to test hypotheses regarding the DIF on the basis of ethnic background and among the elderly Hispanics across time points. Results: Hispanics appear to express positive affect differently than non-Hispanic Whites. On the 20-item scale, Hispanics under responded to items measuring positive affect. Item bias was also found for one positive affect question in the 10-item subset. Among the Hispanic sub-population, we also observed item response bias for the positive affect items across time. A 12-item subset tested for DIF displays an acceptable amount of item bias across ethnic groups and across time for the Hispanic sample. Conclusions: Attempts to make substantive comparisons about the relative prevalence of depression symptoms in elderly Hispanic and non-Hispanic sub-populations appears to be limited by the lack of measurement invariance in the full CES-D. Comparisons across time for elderly Hispanics also appear problematic.