Measuring psychological flexibility and cognitive defusion in individuals with acquired brain injury

Purpose Acceptance and Commitment Therapy (ACT) is used increasingly for individuals with psychological distress following acquired brain injury (ABI) in different countries. However, questionnaires measuring ACT-processes are often not validated for this patient group and need cross-cultural validation. This study investigated the psychometric properties of the Acceptance and Action Questionnaire for Acquired Brain Injury (AAQ-ABI; measuring psychological flexibility related to thoughts and feelings about ABI) and the Cognitive Fusion Questionnaire (CFQ-7; measuring cognitive defusion). Materials and methods Score distribution, reliability, and convergent validity of the AAQ-ABI and the CFQ-7 were examined in Dutch individuals with ABI. Results Seventy-three patients with ABI were included. The AAQ-ABI showed good reliability (Cronbach's alpha = 0.87) and the CFQ-7 excellent reliability (Cronbach's alpha = 0.97). Both did not show a floor or ceiling effect, nor a skewed distribution. There were strong to moderate correlations between the questionnaires and measures of psychological flexibility, mood, quality of life, and value-driven behavior (AAQ-ABI: r = -0.70-0.81; CFQ-7 = -0.67-0.84). Inter-item total correlations indicate that the questions within each questionnaire measured the same construct (AAQ-ABI: r = 0.40-0.78; CFQ-7: r = 0.84-0.93). Conclusions The current study shows that the Dutch AAQ-ABI and CFQ-7 have acceptable to good psychometric properties when measuring psychological flexibility and cognitive defusion in patients with ABI.