The mediating effect of pain catastrophizing and perceived injustice in the relationship of pain on health-related quality of life in breast cancer survivors

Background: The importance of cognitive appraisals in the effectiveness of pain coping is well established. Two key variables in these appraisal processes are pain catastrophizing (PC) and perceived injustice (PI), which are known to increase the risk of long-term disability and aggravate the pain-related distress through maladaptive behavioral responses. However, to date, the mediating effects of these appraisals have not been examined concurrently in the breast cancer survivor (BCS) population, nor have they been related to health-related quality of life (HRQoL). Methods: Using cross-sectional data from 110 BCS, structural path analyses were used to examine the mediating effects of PC and PI in the relationship of pain on the HRQoL in BCS. Results: Results demonstrated a significant direct effect of pain and PI on HRQoL combined with a significant indirect effect through PI, but not through PC. An increase in pain is suggested to result in a decrease in quality of life. On the other hand, an increase in pain also is suggested to increase the PI. A similar relation with PC was not retained as significant. Conclusion: The relative salience of PI as a mediator of HRQoL underscores the fact that PI is not only understudied but also underappreciated and undertreated in the BCS population. The results of our study warrant replication across longitudinal studies but continue to expand upon the evidence of the multifactorial nature of pain coping in BCS.