P–491 The mediator role of pain-related psychological inflexibility in the relationship between psychopathological symptoms and pain intensity in endometriosis
Authors: Galhardo A , Monteiro B , Carolino N , Cunha M 
Published: August 2021

Abstract

Study question
Does pain-related psychological inflexibility play a role in the relationship between psychopathological symptoms (depression, anxiety, stress) and pain intensity in women with endometriosis?

Summary answer
Pain-related psychological inflexibility acts as a mediator exclusively between depressive symptoms and pain intensity. Psychopathological symptoms did not reveal a direct effect on pain intensity.

What is known already
Endometriosis is a chronic and incapacitating condition frequently involving the experience of pain (e.g., dysmenorrhea, ovulation pain, dyspareunia, chronic pelvic pain). Women dealing with endometriosis may present impaired health-related quality of life and psychological distress, with depressive, anxiety, and stress symptoms being commonly reported. Pain-related psychological inflexibility involves emotion regulation processes, such as avoidance of pain and cognitive fusion with pain. Cognitive and behavioural processes influence the relationship between pain and psychopathological symptoms, and pain-related psychological inflexibility showed to be an underlying mechanism in this relationship.

Study design, size, duration
Cross-sectional study. Participants’ recruitment was completed through the Associação Portuguesa de Apoio a Mulheres com Endometriose and the Associação Portuguesa de Fertilidade (endometriosis and infertility patients’ associations). Inclusion criteria were age (18 years or older) and an endometriosis medical diagnosis (self-reported). Data collection occurred between February 2018 and May 2018.

Participants/materials, setting, methods
A sample encompassing 209 women with an endometriosis diagnosis completed online a sociodemographic questionnaire, the Depression, Anxiety and Stress Scales (DASS – 21), the Numeric Pain Rating Scale (NPRS), and the Psychological Inflexibility in Pain Scale (PIPS-PT). Descriptive and correlational analyses were carried out using SPSS v. 26, and path analyses were estimated in AMOS (v. 24) with bootstrap procedures (2000 samples).

Main results and the role of chance
Participants’ age ranged from 18 to 50 years old with a mean of 34.03 (SD = 6.44) years. The majority of participants were married (n = 112; 53.6%), followed by single (n = 54; 25.8%). Regarding years of education, a mean of 14.62 years (SD = 2.80) was found. Participants reported that their endometriosis diagnosis had been established for 4.55 years (SD = 4.56). Correlation analyses showed that depressive, anxiety and stress symptoms were significantly and positively associated with pain intensity and pain-related psychological inflexibility. A mediation analysis was conducted to examine whether pain-related psychological inflexibility mediated the effect of psychopathological symptoms on pain intensity. Paths showing not to be statistically significant were removed. The final model defining an effect of depressive symptoms on pain intensity mediated by pain-related psychological inflexibility explained 26% of the variance. This model showed a good fit to the empirical data: χ2(5) = 10.75, p = .057, CMIN/DF = 2.15; TLI = .98; CFI = .99; RMSEA = .07, 95% CI = .00 to .14. Depressive symptoms predicted elevated pain intensity fully through higher pain-related psychological inflexibility (b = .05; SEb = .01; Z = 8.45; p &lt; .001; β= .51).

Limitations, reasons for caution
Although path analysis is a powerful statistical technique, our findings rely on cross-sectional and self-report data. The study was disseminated through patients’ associations, limiting the inclusion of people who do get in touch with such organizations. Moreover, online recruitment tends to recruit participants with more access to online platforms.
Wider implications of the findings: Pain-related psychological inflexibility seems to be a relevant construct to be addressed in the psychological assessment of women dealing with endometriosis. Furthermore, results suggest the relevance of targeting emotion regulation processes, and not only focus on reducing pain, in pain management interventions.

Trial registration number
N/A.