Psychometric evidence of the Acceptance and Action Questionnaire-II (AAQ-II): an item response theory analysis in university students from Chile

Álvaro I. Langer, Fernando P. Ponce, Jorge L. Ordóñez-Carrasco, Reiner Fuentes-Ferrada, Scarlett Mac-Ginty, Jorge Gaete, Daniel Núñez*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Experiential avoidance (EA) is a psychological mechanism associated with several mental health disorders and is regarded as a relevant target by third-generation cognitive behavioral therapies. It has been mainly assessed through self-report questionnaires, and the AAQ-II is the most used tool. Its psychometric evidence has been mostly tested through the classical test theory (CTT) and very scarcely assessed through Item Response Theory (IRT). Methods: We used the Graded Response Model to examine its psychometric properties in Spanish-speaking university students (n = 1503; women = 995 (66.2%), mean age = 19.29, SD = 2.45). We tested whether the empirical data fit the model’s predictions and estimated the dispersion of persons and items along the experiential avoidance continuum. Moreover, we examined category probability curves to identify the response probability of each answer. Likewise, an item-person map was made where the measurement of persons and items, both on the same scale and along the experiential avoidance continuum, could be observed jointly. Finally, we tested the gender invariance of the scale. Results: We found that the values of the individuals and the items were in the established range to be considered an adequate measure of EA. Additionally, we observed high discrimination indices for all items. The current version with seven answer options could not be optimal and should be tested in future studies. Finally, we found evidence of differential functioning by gender in one of the seven items of the instrument. Conclusions: Our results indicate that the AAQ-II is a suitable tool for measuring EA and accurately classifying and differentiating EA levels in university students.

Original languageEnglish
Article number111
JournalBMC Psychology
Volume12
Issue number1
DOIs
StatePublished - 2024

Bibliographical note

Publisher Copyright:
© The Author(s) 2024.

ASJC Scopus subject areas

  • General Psychology

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