Structural equation modelling provides insights to understand the construct of chronic pain in women with rheumatoid arthritis

Objectives: We aimed to adopt a multidimensional approach and investigate the interconnections between biomarkers (cytokines, matrix metalloproteinases, and cortisol) and psychosocial aspects considering pain acceptance, the individual construct of pain perception in terms of blood inflammation biomarkers, anxiety, self-efficacy, and functional performance and to define the quality of life (QoL) in women with rheumatoid arthritis (RA).

Methods: An observational cross-sectional study with a total of 42-RA participants, with chronic pain and 42-women without rheumatic diseases or chronic pain were included. A structural equation model was used to investigate the association between independent variables.

Results: Women with RA presented high blood biomarker levels, representing an intense inflammatory process. The participants with RA reported moderate pain most of the time, a worsening QoL, functionality, engagement in activities, and a willingness to live with pain and self-efficacy. It was found that the higher the chronic pain, the greater the intensity of pain perceived by these women with RA, as well as, the worse the functionality, the higher the perceived pain.

Conclusions: The exacerbation of pain perception leads to worsening of the experience of chronic pain. The new construct of pain experience should include functionality as a crucial factor in understanding the mechanisms underlying pain.