Psychometric Properties of the Questionnaire Epistemic Trust in People With Mild to Moderate Intellectual Disabilities or Borderline Intellectual Functioning

Background To assess epistemic trust in people with intellectual disabilities, we adapted the Questionnaire Epistemic Trust (QET) for people with mild to moderate intellectual disabilities or borderline intellectual functioning (MMID/BIF). Method We investigated the factor structure, the reliability and construct validity in 147 adults. Results We replicated the 4‐factor structure, after excluding four items with low factor loadings. Internal consistency was α = 0.58 for Hypervigilance, and ranged from α = 0.74 to 0.81 for the other subscales. Subscale test–retest reliability ranged from 0.504 to 0.747. No convergent validity was found with the Reflective Functioning Questionnaire (RFQ). Discriminant validity was confirmed with the Scale of Emotional Development‐Questionnaire (SED‐Q), Scale of Emotional Development‐Short (SED‐S) and Autism Spectrum Quotient‐10 (AQ‐10), but not with General Social Trust (GST). Discussion The QET is promising for assessing epistemic trust of people with MMID/BIF at subscale level. Refining the items with a figurative expression seems needed.