Perceived Injustice and Chronic Pain Acceptance: Are We Measuring Two Separate Constructs or Opposite Poles of the Same Dimension?

Abstract

Perceived injustice has recently emerged as an important construct in the chronic pain literature. Perceived injustice has been shown to be a risk factor for various problematic pain outcomes, such as increased pain severity, depressive symptoms, and pain-related disability. At present, research on perceived injustice in chronic pain is lacking a theoretical model to facilitate understanding of its influence on chronic pain outcomes. It has been suggested that it might be useful to conceptualize perceived injustice within the psychological flexibility model of chronic pain.Indeed, there is preliminary evidencethatperceived injustice is negatively related to chronic pain acceptance, which is an important process within this model; however, the nature of this association is uncertain at present. In particular, it is unclear whether current measures of perceived injustice and chronic acceptance simplyreflect different poles of the same dimension, or theoretically separate, but related, constructs. This study aims to further examine the relation between perceived injustice and pain acceptance. The sample consisted of 847adults who suffer from chronic pain. Several competing measurement models were tested by means of confirmatory factor analysis. Results indicate that these two constructs appear to be two closely related constructs rather than two opposite poles of the same dimension. Implications of these findings for future research will be discussed.