Sensitivity to Pain Traumatization: A Higher-Order Factor Underlying Pain-Related Anxiety, Pain Catastrophizing and Anxiety Sensitivity among Patients Scheduled for Major Surgery

BACKGROUND: The present article addresses two related developments in the psychology of pain, and integrates them into a coherent framework to better understand the relationship between pain and trauma. The first is an emerging conceptualization regarding the nature of the hierarchical organization of major pain-related anxiety constructs. The second is the theoretical rationale and empirical evidence linking pain and symptoms of post-traumatic stress disorder.OBJECTIVES: To explore the underlying hierarchical factor structure of commonly used pain-related anxiety measures including the Pain Anxiety Symptoms Scale (PASS-20), the Pain Catastrophizing Scale (PCS), and the Anxiety Sensitivity Index (ASI); and to relate this structure to post-traumatic stress disorder in patients scheduled for major surgery.METHODS: Measures were completed by 444 patients scheduled to undergo major surgery. Exploratory factor analysis and subsequent higher-order analysis using the Schmid-Leiman transformation were conducted to investigate the underlying factor structure of the ASI, the PCS and the PASS-20.RESULTS: Twenty items from the ASI, the PASS-20 and the PCS loaded exclusively on one higher-order factor. The authors suggest the term ‘sensitivity to pain traumatization’ (SPT) for the underlying construct based in part on the strong, significant positive correlation between SPT scores and scores on the Post-traumatic Stress Disorder Checklist – Civilian Version. Finally, the total SPT score was significantly higher for patients with a history of pain than for those without a history of pain, both before surgery and one year after surgery. SPT describes the propensity to develop anxiety-related somatic, cognitive, emotional and behavioural responses to pain that resemble features of a traumatic stress reaction. Together, the results of the present study provide preliminary evidence for the construct validity of SPT.