Abstract
BACKGROUND: Recently, a new classification system for chronic pain was included in the 11th edition of the International Classification of Diseases (ICD-11). This study aims to investigate how expectancies of coping, that is pain catastrophizing and general self-efficacy, are associated with ICD-11 chronic pain categories in a large pain clinic population. Furthermore, we investigate how coping expectancies are associated with pain-related disability, cross-sectionally and longitudinally across the novel pain classifications. METHODS: The sample was retrieved from the Oslo University Hospital Pain Registry and included baseline data from 2875 chronic pain patients and 12-month follow-up data for 920 patients. Demographic and clinical variables were compared across the ICD-11 chronic pain categories through ANOVA. Multiple regression models were carried out to investigate cross-sectional and longitudinal associations. RESULTS: With the exception of age, our data showed no significant differences across the ICD-11 chronic pain categories. Coping expectancies were associated with disability at baseline. At 12-month follow-up, coping expectancies did not predict pain-related disability when controlling for baseline levels of disability, pain intensity and pain duration. Pain classification (primary vs secondary) did not contribute significantly to the models. Helplessness had the strongest simple relationship to disability, compared with global pain catastrophizing and its additional subscales, both cross-sectionally and longitudinally. CONCLUSION: Coping expectancies, pain intensity and pain-related disability appear similar across the novel chronic pain classifications, indicating that all pain patients may benefit from targeting these variables. Consistent with recent developments in stress theory, helplessness and self-efficacy were cross-sectionally associated with negative pain outcomes. SIGNIFICANCE: Levels of coping expectancies, demographic characteristics, pain-related disability and pain intensity are similar across all ICD-11 chronic pain diagnostic categories. Thus, chronic primary pain is not stronger associated with psychosocial factors such as catastrophizing and self-efficacy than chronic secondary pain. Therefore, chronic pain patients, independent of diagnosis, may benefit from the assessment of these psychosocial factors and targeted interventions such as CBT should be considered.