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 (X(2) = 41.27 [df = 16, p = .001], X(2) /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 (X(2) = 41.70 [df = 16, p < .001], X(2) /df = 2.61, CFI = 0.98, GFI = 0.97, RMSEA = 0.06, SRMR = 0.04). The model for older group indicated measurement noninvariance between Chinese and Korean immigrants (ΔX(2) = 17.86, Δdf = 5, p = .003, CFI = 0.972, ΔCFI = 0.009). The items "hopeless," "restless," and "depress," were significantly nonequivalent between the two groups. CONCLUSIONS: Clinicians/researchers should be aware of the potential risk for misclassification when they screen psychological distress of Chinese or Korean older immigrants. Professionals should pay attention to cross-cultural comparability when interpreting results from the K6.