Rationale: Endometriosis affects 10% of reproductive aged women and causes severe pain and impaired quality of life (QoL). Surgery for endometriosis results in long term symptom relief in only 40% of women. QoL in endometriosis improves after surgery, but not to the level of healthy women. Mediators in QoL include pain intensity, pain cognitions, and stress. In a preliminary study, patients with negative pain cognitions reported higher pain intensities compared to patients with positive pain cognitions. This indicates that psychological factors explain considerable variance in pain, suggesting that changing these factors by psychological interventions may contribute to improving QoL. Cognitive behavioral therapy (CBT) is proven effective as a psychological treatment for pain-related symptoms. QoL after surgery for endometriosis should be improved. Pain cognitions could be psychosocial targets in the treatment of endometriosis related symptoms. We hypothesize that CBT focusing on cognitions towards pain for women undergoing surgery for endometriosis improves pain cognitions, leading to improvement of QoL.~Objective: The primary objective of this study is to investigate whether usual care combined with CBT improves QoL in patients undergoing surgery for endometriosis compared to usual care only. Secondary objectives are to investigate whether pain intensity, pain cognitions, perceived stress, fatigue and objectively measured cortisol levels mediate the effects of CBT on QoL in both groups.~Study design: In a randomized controlled trial, 100 endometriosis patients undergoing surgery will be randomized between usual care with CBT (CBT group) and usual care only (control group). Women in the CBT group will receive, in addition to usual care, one pre-surgery and six post-surgery sessions of CBT, aimed at positively influencing mediators of QoL. Women in the control group will receive only usual care. Follow-up will be 7,5 months. In both groups QoL, pain intensity, pain cognitions, fatigue, perceived stress (using questionnaires) and objective stress (assessing cortisol in a hair sample) will be assessed at baseline assessment, T1 (two weeks after completion of all CBT sessions) and T2 (follow-up). Recruitment and treatment of patients will take place in Rijnstate hospital and Radboud University Medical Center (UMC).~Study population: Healthy female volunteers aged 18-50 years with an indication for endometriosis surgery due to endometriosis associated pain.~Intervention: Cognitive behavioral therapy administered in a total of seven sessions.~Main study parameters/endpoints: The difference in Quality of Life at the last measurement compared to baseline assessment.~Nature and extent of the burden and risks associated with participation, benefit and group relatedness: The control group will receive usual care. The intervention group will receive usual treatment plus a total of seven sessions of CBT. In addition, all participants are asked to fill in seven questionnaires at baseline assessment, T1 (two weeks after completion of all CBT sessions) and T2 (follow-up): the EHP-30, SF-36, PSC, PASS, CIS, NRS and PSS. Furthermore, the researcher will carefully collect a scalp hair sample of at least 0,5 cm thickness. This will be done at baseline assessment, T1 and T2. The hair sample will be analyzed for cortisol levels in a laboratory.
Endometriosis affects 10% of reproductive aged women and causes severe pain and impaired quality of life (QoL). Surgery for endometriosis results in long term symptom relief in only 40% of women.~QoL in endometriosis improves after surgery, but not to the level of healthy women. Mediators in QoL include pain intensity, pain cognitions, and stress. In a preliminary study, patients with negative pain cognitions reported higher pain intensities compared to patients with positive pain cognitions. This indicates that psychological factors explain considerable variance in pain, suggesting that changing these factors by psychological interventions may contribute to improving QoL. Cognitive behavioral therapy (CBT) is proven effective as a psychological treatment for pain-related symptoms. The primary objective of this study is to investigate whether usual care combined with CBT improves QoL in patients undergoing surgery for endometriosis compared to usual care only. Secondary objectives are to investigate whether pain intensity, pain cognitions, perceived stress, fatigue and objectively measured cortisol levels mediate the effects of CBT on QoL in both groups.~In a randomized controlled trial, 100 endometriosis patients undergoing surgery will be randomized between usual care with CBT (CBT group) and usual care only (control group). Women in the CBT group will receive, in addition to usual care, one pre-surgery and six post-surgery sessions of CBT, aimed at positively influencing mediators of QoL. Women in the control group will receive only usual care. Follow-up will be 7,5 months. In both groups QoL, pain intensity, pain cognitions, fatigue, perceived stress (using questionnaires) and objective stress (assessing cortisol in a hair sample) will be assessed at baseline assessment, T1 (two weeks after completion of all CBT sessions) and T2 (follow-up). Recruitment and treatment of patients will take place in Rijnstate hospital and Radboud University Medical Center (UMC).