Measurement equivalence of the Kessler 6 Psychological Distress Scale for Chinese and Korean immigrants: Comparison between younger and older adults

Abstract

Objectives: The Kessler 6 (K6) Psychological Distress Scale is a well-known instrument to screen for psychological distress of general populations. It is critical to perform the equivalence test of the K6 for Asian immigrant subgroups. Methods: The 2012 California Health Interview Survey data were used (N = 1,210; Chinese = 640, Koreans = 570). Among 1,210, 734 were younger (18–64 years) and 476 were older (65+) adults. It was examined whether parameters in the measurement model is equivalent across the two groups, using multiple-group analysis. The equivalence tests for Chinese and Koreans were separately performed based on different age groups (younger [18–64] vs. older [65+]). Results: The younger group had good model fit (X2 = 41.27 [df = 16, p =.001], X2/df = 2.58, Comparative Fit Index [CFI] = 0.99, Goodness of Fit Index [GFI] = 0.98, root mean square error or approximation [RMSEA] = 0.05, standardized root mean residual [SRMR] = 0.03), and the older group also showed good model fit (X2 = 41.70 [df = 16, p