Of subjects who used herbal medications, 72% were also receiving prescription medications. The most popular herbal medications were echinacea, ginseng, and ginkgo.

CURRENT REVIEW
The current systematic review generally supports the use of Chinese herbal medicine for the treatment of primary dysmenorrhea, but it also highlights some of the difficulties in applying Western standards of evidence-based medicine to treatments used for thousands of years in the Far East. The review considered only trials of treatment of primary dysmenorrhea, and of interest, focused on trials in which women had previously received nonsteroidal anti-inflammatory medications (NSAIDs) or hormones for dysmenorrhea. The main study outcome was the reduction in pain associated with treatment; others included additional analgesia and quality of life.

Thirty-nine trials of Chinese herbal medication for dysmenorrhea were fully reviewed, but many of these trials had methodologic problems. In particular, 18 trials were not randomized, and 4 other trials failed to mention randomization.

Most research was conducted in mainland China, and the use of traditional Chinese medicine significantly affected the way the research was conducted. Chinese medicine emphasizes a different approach to patient symptoms and diagnosis compared with Western medicine, with a greater emphasis on clusters of symptoms across different organ systems. The clusters of symptoms in most of the studies examining the treatment of dysmenorrhea were consistent with the Western definitions of dysmenorrhea, but 19 studies used variations in the herbal treatment protocol based on individual participant's diagnostic patterns.

Only 3 studies compared Chinese herbal medications with placebo; most of the other trials compared herbal treatments with:

• NSAIDs;
• Hormonal therapy; or
• Other Chinese herbal treatments.

The size of all included studies was small, with only 1 trial involving more than 100 patients. Most participants in the trials received multiple herbal treatments, although the dosage ranges of these many different therapies (19 main herbs were investigated) generally conformed to standard Chinese practice.

Results of The Cochrane Review: Regardless of these study limitations, Chinese herbal medications were generally effective against dysmenorrhea. Herbal medications were approximately twice as likely to improve pain compared with conventional therapy. In particular, Meiguihua (Rosa rugosa Thunb) was demonstrated to reduce dysmenorrhea-associated symptoms (pain, stress, and anxiety) over a 6-month time course:

Chinese herbal medications can also be rapidly effective against dysmenorrhea; one trial demonstrated an analgesic effect within 30 minutes. There was evidence as well that Chinese herbal medications may reduce patients' use of other analgesic medications for dysmenorrhea.

Chinese herbal medications were superior to over-the-counter health supplements in improving dysmenorrhea. A tailored herbal regimen was more than twice as likely to improve dysmenorrhea as a routine herbal preparation available without a prescription. However, the lack of standardization of herbal preparations and t that there was little confirmatory research to establish the efficacy of a specific herbal remedy precluded any recommendation for a particular treatment regimen. Chinese herbal medication was also found to be superior to acupuncture for dysmenorrhea in 2 trials.

Adverse events associated with study therapy were reported in only 8 of the 39 trials. There were no significant events found with either Chinese herbal medications or the comparator agents.

How to apply the results of this meta-analysis in Western medical practice is a difficult dilemma. First, the methodologic limitations of these studies must be considered. More practically speaking, it seems clear that some experience with Chinese herbal medications would be necessary before effectively prescribing these treatments for dysmenorrhea. Although the herbal formulas may be generally effective, they involve multiple agents in each treatment regimen, and this regimen appears to be most effective when it is individualized to each patient's symptoms.

CONTEXT - OTHER RESEARCH OF CHINESE HERBAL MEDICATION
Given the barriers of translating research about Chinese herbal medications into Western medical practice, healthcare providers would be well-advised to focus on objective, evidence-based reviews by individuals with some expertise in the field of Chinese medicine. The Cochrane Database of Systematic Reviews has previously examined the potential role of Chinese herbal medications for the treatment of type 2 diabetes. This review examined 66 different trials involving 8302 participants. Similar to the current review regarding dysmenorrhea, there was significant heterogeneity between studies in almost every aspect, and the methodologic quality of studies was generally low. The studies included 69 different treatments, and the majority of studies compared herbal medications with established medications for diabetes, usually sulfonylureas.

At least 6 different herbal preparations were demonstrated to have hypoglycemic effects, and 15 herbal preparations were synergistic with traditional diabetes medications in improving glycemic control. Ginseng, which is one of the most popular supplements in the United States, was not effective in improving glucose control. Despite these generally positive results, the review recommended further study of any of the Chinese herbal medications prior to their routine use in treating type 2 diabetes.

Chinese Herbs and the Common Cold: Healthcare providers have multiple options to effectively treat dysmenorrhea and type 2 diabetes, but there are no truly effective treatment options for the common cold. Another systematic review examined the efficacy of Chinese herbal medications for this familiar malady. Researchers focused on 14 studies involving 2440 participants. This research was limited because herbal medications were compared with drugs that were considered to be effective for viral upper respiratory infections rather than with placebo, which would have been a more effective means to study this issue. Another overall limitation of these studies was the poor quality of randomization in the clinical trials.

Nonetheless, this review also provides some positive results for Chinese herbal medications. Five studies demonstrated superior efficacy of herbal preparations over active control medications in promoting recovery from the common cold, and another 8 studies demonstrated equivalence of the herbal medication and active control in this outcome.

CONCLUSION
Traditional Chinese medicine has proven itself through the test of time, and it has much to offer patients around the world. However, the previous studies of the efficacy of Chinese herbal medications as well as the current review of herbal preparations for dysmenorrhea highlight the difficulty of translating medical treatment across cultures. The currently available research is not only limited regarding methodology in determining the efficacy of Chinese herbal medications, but also of importance, many of these studies do not adequately address concerns regarding tolerability and safety.