Many national surveys have found substantial differences in self-reported overall health between Spanish-speaking Hispanics and other racial/ethnic groups. However, because cultural and language differences may create measurement bias, it is unclear whether observed differences in self-reported overall health reflect true differences in health.
This study uses a cross-sectional survey to investigate psychometric properties of the Short Form-36v2 for subjects across 4 racial/ethnic and language groups. Multigroup latent variable modeling was used to test increasingly stringent criteria for measurement equivalence.
Our sample (N=1281) included 383 non-Hispanic whites, 368 non-Hispanic blacks, 206 Hispanics interviewed in English, and 324 Hispanics interviewed in Spanish recruited from outpatient medical clinics in 2 large urban areas.
We found weak factorial invariance across the 4 groups. However, there was no evidence for strong factorial invariance. The overall fit of the model was substantially worse (change in Comparative Fit Index >0.02, root mean square error of approximation change >0.003) after requiring equal intercepts across all groups. Further comparisons established that the equality constraints on the intercepts for Spanish-speaking Hispanics were responsible for the decrement to model fit.
Observed differences between SF-36v2 scores for Spanish-speaking Hispanics are systematically biased relative to the other 3 groups. The lack of strong invariance suggests the need for caution when comparing SF-36v2 mean scores of Spanish-speaking Hispanics with those of other groups. However, measurement equivalence testing for this study supports correlational or multivariate latent variable analyses of SF-36v2 responses across all the 4 subgroups, as these analyses require only weak factorial invariance.
*Center for Healthcare Research and Policy, Case Western Reserve University at the Metro Health System
†Department of Medicine
‡Department of Physical Medicine and Rehabilitation, School of Medicine, Case Western Reserve University, Cleveland, OH
§Department of Physical Therapy and Human Movement Sciences
∥Division of General Internal Medicine, Department of Medicine
¶Institute for Healthcare Studies, Feinberg School of Medicine, Northwestern University, Chicago, IL
Supported by NIH/NIA grant R01-AG022459.
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Reprints: Joseph J. Sudano, PhD, Center for Health Care Research and Policy Case Western Reserve University at The Metro Health System, 2500 Metro Health Drive R236A, Cleveland, OH E-mail: email@example.com.