Pain-Related Disability in Chronic Pain Patients: Examining the Roles of Pain Intensity, Pain Catastrophizing and Self-Efficacy through a Moderated Mediation Analysis

Abstract

Objective: The literature on chronic pain suggests that pain catastrophizing and self-efficacy are important psychological factors involved in chronic pain. The current study aimed to explore the role of pain catastrophizing and self-efficacy in the relationship between pain intensity and pain-related disability. A hypothetical model was proposed in order to investigate whether the association between pain intensity and pain-related disability was mediated by self-efficacy, as well as examining the potential moderator effects of pain catastrophizing on the direct association between pain intensity and pain-related disability, and on the possible mediation. Methods: Analyses were based on a sample of 3.739 outpatients from the Oslo University Hospital Pain Registry (OPR). The OPR is a comprehensive collection of self-reported data on pain characteristics, pain management and physical and mental health. A cross-sectional study was conducted using Baron and Kenny’s method of mediation and moderation to examine a simple mediation effect and simple moderation effects. Furthermore, Hayes’ conditional process analysis was applied in order to examine a possible moderated mediation effect (conditional indirect effect). The measures included a modified version of the Oswestry Disability Index to assess pain-related disability, a 0-10 Numeric Rating Scale to assess usual pain intensity, The General Self-Efficacy Scale to assess perceived self-efficacy, and The Pain Catastrophizing Scale to assess pain catastrophizing and negative orientation towards pain stimuli. Results: The results gave no indication of a moderated mediation effect nor any moderator effects. The simple mediation analysis revealed that self-efficacy partly mediates the association between pain intensity and pain-related disability. Conclusions: In accordance with previous research, the results indicated that self-efficacy partly mediates the association between pain intensity and pain-related disability. On the other hand, the results were in disfavor of pain catastrophizing operating as a moderator as proposed in the hypothesized model. The results could imply that there is a less complex association between pain intensity and pain-related disability than the one postulated in our hypothesized model, or that the examined variables relate to each other in a different way than what we postulated.