Psychometric Properties of the Spanish Adaptation of the Externalizing Spectrum Inventory–Brief Form (ESI-BF)

The Externalizing Spectrum Inventory–Brief Form (ESI-BF) measures tendencies toward disinhibition, lack of control, aggression, and substance use. This study adapts the ESI-BF to the Spanish population and assesses its psychometric properties. The study included 742 community adults obtained by stratified random sampling with proportional allocation according to gender, age, and geographical area of the Spanish territory and a clinical sample consisting of 333 patients. All participants completed the Personality Inventory for Diagnostic and Statistical Manual of Mental Disorders, fifth edition (PID-5) and the Alcohol Substance Dependence Severity Scale, in addition to the Spanish version of the ESI-BF. Reliability was quantified using McDonald’s omega and Cronbach’s α reliability coefficients. Validity evidences were studied applying confirmatory factor analysis (CFA) and correlations. Results indicated adequate reliability of scores on the ESI-BF’s general factors and most of its facets. Regarding internal structure, and in line with previous studies, both symmetric and S-1 hierarchical two-subfactor (bifactor) emerged as the best-fitting models. Considering both criticisms of symmetric models and parsimony, the S-1 bifactor model, which showed configural invariance across gender and samples, was retained. Validity evidence based on the relationship with other measures of personality and alcohol consumption show correlations values theoretically expected in both clinical and community samples. Findings suggest that the Spanish adaptation of the ESI-BF shows functional near-equivalence to the original version. Its effective psychometric properties make it useful instrument for further research related to the externalizing spectrum.