Construct validity of the short inventory of problems among Spanish speaking Hispanics

Research on ethnic health disparities requires the use of psychometrically sound instruments that are appropriate when applied to ethnically diverse populations. The Short Inventory of Problems (SIP) assesses alcohol-related consequences and is often used as a measure to evaluate intervention effectiveness in alcohol research; however, whether the psychometric properties of this instrument are comparable across language and ethnicity remains unclear.

Multi-group confirmatory factor analysis (MGCFA) was used to test for the invariance of the measurement structure of the SIP across White Non-Hispanic English speaking (N=642), Hispanic English speaking (N=275), and Hispanic Spanish speaking (N=220) groups.

The MGCFA model in which factor loadings, measurement intercepts, and item residuals were constrained to be equal between English speakers and Spanish speakers exhibited a reasonable fit to the data, χ(2)(221)=1089.612 p<.001, TLI=.926; CFI=.922, RMSEA=.059 (90% CI=.055-.062). The ΔCFI supported strict factorial invariance, ΔCFI=.01, across groups; no significant group differences were found between factor loadings, measurement intercepts, or item residuals between English speakers and Spanish speakers.

This study extends the existing confirmatory factor analysis results of the SIP by providing additional data to inform the utility of the SIP among Hispanics. Strict factorial invariance between Spanish and English speakers is necessary to: conclude that the underlying constructs have the same meaning across groups; test for group differences in the latent variables across groups; and presume that group differences are attributable only to true differences between groups. Thus, the SIP is strongly supported for evaluating the effectiveness of alcohol treatment among Hispanics.