Catastrophizing: a predictor of persistent pain among women with endometriosis at 1 year.

Background: Endometriosis is the most common gynecological diagnosis among women with chronic pelvic pain, but the underlying mechanisms of endometriosis-associated chronic pelvic pain remain unclear. Therefore, the objective of this study was to determine the biopsychosocial predictors of pain improvement among women with endometriosis.

Methods: One hundred and fifteen women who presented for treatment of endometriosis-associated chronic pelvic pain at a tertiary referral center at a university-based hospital participated in this prospective observational study of clinical practice. Participants completed questionnaires assessing pain, mental health and catastrophizing at entry and 1 year follow-up. The main outcome measure assessed was the interval change in pain report using the McGill pain 1uestionnaire.

Result(s): On average, participants experienced a 37.4% reduction in interval pain (P < 0.001). Adjusted for baseline pain, nulliparity (P = 0.002) and catastrophizing (P = 0.04) were associated with decreased probability of interval improvement in pain. Those referred for physical therapy had less interval pain improvement (P = 0.04). However, undergoing hysterectomy was a strong predictor of improvement in pain (P = 0.008).

Conclusion(s): Our study suggests that chronic pain in endometriosis may be more akin to other idiopathic pain disorders. Specifically, biopsychosocial variables, such as catastrophizing, play an important role in reported severity. Further research on biopsychosocial correlates of chronic pelvic pain in endometriosis is warranted.