Optimizing efficiency of psychopathology assessment through quantitative modeling: development of a brief form of the Externalizing Spectrum Inventory.

The Externalizing Spectrum Inventory (ESI; Krueger, Markon, Patrick, Benning, & Kramer, 2007) provides for integrated, hierarchical assessment of a broad range of problem behaviors and traits in the domain of deficient impulse control. The ESI assesses traits and problems in this domain through 23 lower order facet scales organized around 3 higher order dimensions, reflecting general disinhibition, callous aggression, and substance abuse. The full-form ESI contains 415 items, and a shorter form would be useful for questionnaire screening studies or multimethod research protocols. In the current work, we employed item response theory and structural modeling methods to create a 160-item brief form (ESI-BF) that provides for efficient measurement of the ESI's lower order facets and quantification of its higher order dimensions either as scale-based factors or as item-based composites. The ESI-BF is recommended for use in research on psychological or neurobiological correlates of problems such as risk-taking, delinquency, aggression, and substance abuse, and studies of general and specific mechanisms that give rise to problems of these kinds.