RESUMEN
BACKGROUND: Fibromyalgia (FM) is characterized by chronic widespread pain, fatigue, sleep disturbances, cognitive impairment, and mood disturbance. Both pain catastrophizing and pain self-efficacy have been found to be mediators of pain treatment effectiveness. However, whether pain catastrophizing mediates the association between pain self-efficacy and FM severity remains unclear. AIM: To examine whether pain catastrophizing mediates the association between pain self-efficacy and disease severity in patients with FM. METHODS: This cross-sectional study included the baseline data of 105 people with FM from a randomized controlled trial. Hierarchical linear regression analysis was performed to examine the predictive ability of pain catastrophizing for FM severity. Furthermore, we examined the mediating effect of pain catastrophizing on the association between pain self-efficacy and FM severity. RESULTS: Pain self-efficacy was negatively associated with pain catastrophizing (ß = -.4043, p < .001). FM severity was positively associated with pain catastrophizing (ß = .8290, p < .001) and negatively associated with pain self-efficacy (ß = -.3486, p = .014). Pain self-efficacy had a direct effect on FM severity (ß = -.6837, p < .001) and an indirect effect on FM severity through the effect of pain catastrophizing (ß = -.3352, 95% CI bootstrapping -.5008 to -.1858). CONCLUSION: Pain catastrophizing independently predicts FM severity and mediates the association between pain self-efficacy and FM severity. Pain catastrophizing should be monitored through interventions aimed at improving pain self-efficacy to reduce symptom burden in patients with FM.