Pain acceptance in people with chronic pain and spinal cord injury: Daily fluctuation and impacts on physical and psychosocial functioning

Daily fluctuation in pain acceptance and its impact on the physical and psychosocial functioning of individuals living with spinal cord injury (SCI) and chronic pain has not been examined. We used end-of-day (EOD) diaries and multilevel mixed effects modeling (MLM) to examine the moderating effect of within- and between-person pain acceptance on associations between pain and physical and psychosocial functioning. Individuals with SCI and chronic pain (N = 124) completed seven days of EOD diaries, which included measures of pain acceptance, pain intensity, pain catastrophizing, pain interference, participation in social roles and activities (SRA), depressive symptoms, and positive affect and well-being (PAWB). We found within-person variability in pain acceptance (28% of the total variance) and a significant moderating effect of daily fluctuation in pain acceptance on the same-day pain intensity-SRA association. Within-person changes in pain acceptance were also associated with daily changes in pain interference, depressive symptoms, and PAWB, adjusting for pain intensity and catastrophizing. Findings highlight the potential for daily or momentary assessments of pain acceptance to enhance understanding of how psychological flexibility may contribute to pain-related outcomes. Future studies could further investigate stable and variable characteristics of pain acceptance and their individual contribution to physical and psychosocial functioning. 
Perspective Daily fluctuations in pain acceptance and their association with physical and psychosocial functioning were observed in the lives of individuals with spinal cord injury (SCI) and chronic pain. These findings may guide future studies to inform the development of effective, pain acceptance-focused individualized treatment approaches for chronic pain management in people with SCI.