The role of posttraumatic stress symptoms on chronic pain outcomes in chronic pain patients referred to rehabilitation

Sophie Lykkegaard Ravn,1,2 Henrik Bjarke Vaegter,3,4 Thomas Cardel,1 Tonny Elmose Andersen1 1Department of Psychology, University of Southern Denmark, Odense, Denmark; 2The Specialized Hospital for Polio and Accident Victims, Roedovre, Denmark; 3Pain Research Group, Pain Center South, Department of Anesthesiology and Intensive Care Medicine, Odense University Hospital, Odense, Denmark; 4Department of Clinical Research, University of Southern Denmark, Odense, Denmark Objectives: Posttraumatic stress symptoms (PTSS) are highly prevalent in chronic pain patients and may affect pain symptomatology negatively, but there is still a great need to explore exactly how this occurs. Therefore, this study investigated differences in pain intensity, pain-related disability, and psychological distress between chronic pain patients not exposed to a trauma, patients exposed to a trauma with no PTSS, and patients exposed to a trauma with PTSS. Moreover, the moderating effects of PTSS on the associations between pain intensity and pain-related disability and psychological distress were investigated. Methods: In this cross-sectional cohort study, data were consecutively collected over the course of a year in patients with chronic non-malignant pain referred for multidisciplinary pain rehabilitation at a Danish university hospital pain center using questionnaires assessing pain, pain-related disability, PTSS, anxiety, and depression.Results: The final sample consisted of 682 chronic pain patients, who were divided into three subgroups (no trauma, 40.6%; trauma/no PTSS, 40.5%; trauma/PTSS, 18.9%). Chronic pain patients with PTSS reported significantly higher levels of pain intensity, pain-related disability, depression, and anxiety compared to chronic pain patients without a trauma and chronic pain patients without PTSS. Moreover, PTSS significantly moderated the associations between pain intensity and pain-related psychosocial disability, depression, and anxiety. Conclusion: These results highlight the importance of assessing PTSS in chronic pain patients and suggest that PTSS have a specific influence on the association between pain intensity and more psychosocial aspects of the pain condition. Keywords: chronic pain, posttraumatic stress symptoms, PTSS, PTSD, distress, pain-related disabilit