Predictors of Improvement in Fatigue Following Hysterectomy

INTRODUCTION: Fatigue is a common and debilitating symptom in patients with chronic pelvic pain and endometriosis, and impairs the ability to work and participate in social activities. Previous research in women with endometriosis-associated pelvic pain has shown that the severity of non-menstrual pelvic pain was correlated with severity of fatigue, and women treated with hormonal medication experienced a reduction in fatigue alongside relief from pelvic pain. Fatigue is a key phenotypic feature of central sensitization/nociplastic pain, which is characterized by widespread pain. There is limited data whether fatigue improves following hysterectomy in patients with endometriosis and/or chronic pelvic pain, and whether improvement in fatigue reflects improvement in pelvic pain or widespread pain. OBJECTIVE: To evaluate whether fatigue improves in women undergoing hysterectomy for pelvic pain and whether changes in fatigue are more strongly related to improvement in pelvic pain or widespread pain. METHODS: We conducted a secondary analysis of an observational cohort study of women aged 22–69 years undergoing hysterectomy at an academic tertiary care center for a benign indication. Patients with preoperative moderate to severe pelvic pain, defined as average pelvic pain >=3 on a 0 to 10 numeric rating scale for >3 months before hysterectomy, were included in this analysis. The patients completed validated assessments of pelvic pain, overall body pain, and fatigue preoperatively and 6 months after hysterectomy. Those with complete data at baseline and 6 months were included. Our primary outcome was the degree of improvement in fatigue from baseline to 6 months following surgery, and the primary predictors of interest were change in pelvic pain and change in overall bodily pain between baseline and month 6. General linear models were used with patient age and presence of endometriosis as covariates, and partial eta-squared values were used to compare the strength of the associations between the outcome and predictors. RESULTS: We had 6-month follow-up data from 231 patients who had reported moderate to severe pelvic pain prior to hysterectomy, of whom 55 (23.8%) reported a history of endometriosis. Improvement in overall bodily pain was significantly associated with improvement in fatigue (p<.05; see Figure 1), while improvement in pelvic pain was not (p>.05). Change in bodily pain (eta squared η2=.043) was more strongly associated with improving fatigue than pelvic pain (eta squared η2=.014). Notably, a history of endometriosis was not associated with a change in fatigue postoperatively. CONCLUSIONS: In women undergoing hysterectomy with chronic pelvic pain, we found that pelvic pain, overall body pain, and fatigue improve after hysterectomy. However, greater improvement in overall body pain was a substantially more salient predictor of improvement in fatigue than was improvement in pelvic pain (Table 1).