Patterns of Approach to Activity in 851 Patients With Severe Chronic Pain

Objectives: The Avoidance-Endurance Fast-Screen (AEFS) is a 9-item self-report questionnaire that classifies patients with back pain into 4 activity-related subgroups, based on the Avoidance-Endurance Model of pain. The objective of this study was to translate the AEFS into Danish and investigate its discriminative abilities in a large, diverse patient sample. Materials and Methods: A total of 851 specialist care-seeking patients with severe chronic pain conditions participated in this cross-sectional study. Participants were categorized as showing a “distress-endurance” (DER), “eustress-endurance” (EER), “fear-avoidance” (FAR), or “adaptive” (AR) pattern. Principal component analysis reduced a large number of psychological variables beforehand. Construct and outcome-based validity were explored using multivariate analysis of variance. Results: Of the participants, 33.6% were categorized as DER, 29.4% as EER, 22% as FAR, and 15% as adaptive. Principal component analysis showed the factors activity-related pain behavior, affective distress, and dysfunctional pain thoughts. The AEFS-DK discriminated all 4 subgroups in terms or their pain behavior with EER>DER>AR>FAR. FAR showed less moderate/vigorous activity than DER and EER and more sedentary time than EER. DER and FAR showed higher affective distress, dysfunctional pain thoughts, and poorer outcomes than AR and EER. Conclusion: The results indicate good construct validity of the AEFS-DK discriminating the 4 avoidance-endurance model-related subgroups with respect to approach to activity behavior, psychological variables, and reported physical activity. Concerning outcome-based validity, 2 subgroups DER/FAR and AR/EER could be distinguished with inconclusive results for the eustress-endurance subgroup. Future studies are warranted using longitudinal research designs investigating whether AEFS subgroups differ in terms of treatment effects and long-term prognosis.