EXAMINING RELATIONSHIPS AMONG FM PAIN INTENSITY, CATASTROPHIZING AND INTERFERENCE
BACKGROUND: FM is a persistent, widespread pain condition that is also characterized by tenderness, fatigue, depression, and sleep disturbance. The disease often develops in the third or fourth decade, is highly disabling, and significantly interferes with the ability to participate in meaningful activity. Pain interference describes the effect of pain on the ability to engage in social, emotional, physical, and recreational activities. Pain catastrophizing describes the tendency to overestimate the threat of pain, is characterized by rumination, magnification, and helplessness, can significantly affect the desire to engage in activity. Because chronic pain is a biopsychosocial experience, it is likely that psychosocial variables like catastrophizing can mediate the relationship between pain intensity and pain interference.
METHOD: This study is a secondary analysis of a longitudinal study designed to examine the effect of chronic pain and environmental barriers on community participation (N=521). The random sample of adults aged 18+ was recruited using a population based mailing technique that included 10,000 households (5 zip codes). A subset reporting a diagnosis of FM was used for the secondary analysis (n=70). Pain interference over the last 7 days was measured with the PROMIS-Short Form 8a. Average pain intensity over the last 7 days was measured on an 11 point scale (0 = no pain, 10 = worst pain you can imagine). The Pain Catastrophizing Scale (PCS) was used to measure catastrophizing. Descriptive statistics were used to characterize the sample. Multiple regression analysis was used to examine pain catastrophizing as a mediator.
RESULTS: The sample was primarily female (89%), White (92%), married (41%), and well-educated (66% with Bachelor degree or higher). However, 45% earned less than $20,000/year. Pain intensity was moderately high (X =5.9/10, SD=2.03) as was pain interference (X=28/40, SD=8.7). Pain catastrophizing was moderate (X =15.7/30, SD=6.31). Correlations were moderate between pain intensity and interference (r=44, p =.000), and pain intensity and catastrophizing (r =.41, p=.000), but stronger between pain catastrophizing and pain interference (r =.59, p=.000). Pain intensity and catastrophizing accounted for nearly 40% of the variance in pain interference. However, catastrophizing was not a mediator. Rather it contributed uniquely to the variance in pain interference.
IMPLICATIONS: Being able to participate in activities enhances quality of life and is an important measure of overall health. This study highlights the importance of integrating mind and body treatment of FM. Higher levels of pain catastrophizing and pain intensity can both significantly increase pain interference and reduce quality of life in persons living with FM. Further research exploring methods designed to reduce pain intensity and catastrophizing is needed.