# Controlled Clinical Studies of Combined Oral Contraceptives for Dysmenorrhea in China: A Systematic Literature Review

## TL;DR

This review summarizes clinical studies on combined oral contraceptives for dysmenorrhea in Chinese women, finding them effective and safe.

## Contribution

A systematic review of COC studies in China reveals their efficacy and safety for dysmenorrhea treatment.

## Key findings

- COCs significantly reduced dysmenorrhea symptoms in both primary and secondary cases.
- Abnormal menstrual bleeding was the most common adverse event reported.

## Abstract

Combined oral contraceptives (COCs) can relieve dysmenorrhea, but utilization is low in Chinese women. This systematic literature review was conducted to summarize the design of clinical studies and the effectiveness and safety of COCs for dysmenorrhea in Chinese women.

The PubMed, EMBASE, CNKI, Wanfang, VIP, Chinese clinical trial register, and ClinicalTrials.gov databases were searched for randomized controlled trials (RCTs), non-RCTs, and cohort studies investigating COCs for dysmenorrhea in the Chinese population. A narrative synthesis and descriptive statistics were used to summarize the clinical study designs, intensity of dysmenorrhea symptoms, and safety of COCs for dysmenorrhea in Chinese women.

Twenty-eight clinical studies (24 RCTs, 2 non-RCTs, 2 cohort studies) with 3409 patients were included in this review. Primary (PD) and secondary dysmenorrhea (SD) were investigated in 9 and 18 studies, respectively, and 1 study did not specify the type. Most studies gave cyclic versus continuous COCs (92.9% [n = 26/28] vs. 14.3% [n = 4/28 studies]). Traditional Chinese medicines were common comparators (PD: 66.7% [n = 6/9 studies]; SD: 61.1% [n = 11/18 studies]). Most studies reported intensity of dysmenorrhea symptoms (n = 22/28), usually with the visual analogue scale pain score (59.1% [n = 13/22 studies]). COCs significantly reduced symptoms of dysmenorrhea in PD and SD. Abnormal menstrual bleeding was the most common adverse event (2.4%–51.4%).

COCs are effective for PD and SD in China with an acceptable safety profile. Additional head-to-head comparative trials are needed to clarify the role of COCs versus other treatments in Chinese patients.