Fear-avoidance- and endurance-related responses to pain: development and validation of the Avoidance-Endurance Questionnaire (AEQ).

Aim Of Investigation: Recent research indicated wide variability regarding pain-related cognitive/affective and behavioral responses to pain, showing that fear-avoidance responses (FAR) and endurance-responses (ER) play a prominent role in the maintenance of low back pain (LBP). Until now, there is a lack of reliable and valid instruments covering FAR and ER.

Methods: A pool of 60 items, derived from the Kiel Pain Inventory was answered by 191 LBP patients. Principle components analyses (PCA) was used to explore the factor structure creating the Avoidance-Endurance Questionnaire (AEQ). Validity was calculated using the criteria variables pain intensity, disability, chronic pain grades (CPG) and number of sick days, further self-report measures (Fear-Avoidance Beliefs Questionnaire FABQ, Pain Anxiety Symptoms Scale PASS, Tampa Scale of Kinesiophobia TSK and Beck Depression Inventory BDI) evaluating construct validity.

Results: PCA revealed five AEQ-FAR scales with anxiety/depression, catastrophizing, help-/hopelessness, avoidance of social activities, avoidance of physical activities, and four AEQ-ER scales with positive mood, thought suppression, pain persistence behavior and humor/distraction. All scales revealed high internal consistency. As expected, FAR scales showed positive associations with pain, disability and other FAR variables (correlations between r=.26 and r=.58), whereas ER scales showed negative associations (between r=-.19 and -.48). The only exception referred to positive correlations between both, FAR and ER and pain intensity.

Conclusions: The AEQ has shown as a reliable and valid measure to assess pattern of fear-avoidance and endurance-related responses to pain. Both aspects seem to play a role in the maintenance of LBP.