Reduction of surgery rate in endometriosis patients who take Chinese medicine: a population-based retrospective cohort study.

Objectives: Female patients have frequently utilized Chinese medicine (CM) to treat symptoms that could possibly be related to endometriosis. The objective of this population-based retrospective cohort study was to evaluate the relationship between CM use and subsequent surgery among patients with endometriosis.

Design: A total of 8,283 CM users were identified among the 22,488 endometriosis patients found in the National Health Insurance reimbursement database between 2000 and 2010. A control group was identified and consisted of 8,283 matched nonusers with the same disease. A Cox proportional regression analysis was performed in order to assess risk factors for surgery for the CM users and nonusers.

Results: When compared to nonusers, CM users were significantly less likely to undergo surgery, with a hazard ratio of 0.47 (95% CI=0.421, 0.534) after adjusting for age, occupation, childbirth status, hypermenorrhea, iron-deficient anemia, dysmenorrhea, and amount of conventional medications. Among patients who had undergone surgery, the follow-up time was longer for CM users than for CM nonusers (p<0.001). Moreover, the most frequently used CM single and formula were Cyperus rotundus and Gui-zhi-fu-ling-wan, respectively.

Conclusions: These results suggest that whatever the underlying reason, CM provides an alternative option that reduces the incidence rate of surgery in endometriosis patients.