[Evidence mapping of clinical research on 28 Chinese patent medicines for tension-type headache]

In this study, the evidence mapping methodology was used to systematically retrieve and sort out the clinical research evidence of Chinese patent medicines in the treatment of tension-type headache(TTH), and to understand the distribution of evidence in this field and the basis and quality of evidence. Chinese and English articles on the 28 Chinese patent medicines for TTH, which were recorded in National Essential Medicines List(2018), Medicine Catalogue for National Basic Medical Insurance, Work Injury Insurance, and Maternity Insurance(2020), and Chinese Pharmacopoeia(2020), were retrieved from China National Knowledge Infrastructure(CNKI), Wanfang, VIP, China Biology Medicine disc(CBMdisc), PubMed, EMbase, and Cochrane Library from the establishment to June 2021, followed by descriptive analysis. Then, tables and bubble charts were plotted to analyze the distribution characteristics of evidence. A total of 129 eligible articles were yielded: 126 randomized/non-randomized controlled trials, and 3 systematic reviews. The functions, indications, and composition of the 28 medicines, as well as the proportion of related articles, publication trends, intervention measures, and outcome indicators were compared and analyzed. The results showed that the 28 Chinese patent medicines, composed of 128 Chinese medicinals, can be classified into six categories in terms of function: reinforcing healthy Qi, tranquilizing mind, dispelling stasis, regulating Qi, treating wind, and resuscitating. There are ongoing efforts to study the treatment of TTH with Chinese patent medicine in China, despite of little evidence. The clinical positioning of Chinese patent medicine for TTH is not clear, and clinical research fails to highlight the advantages of Chinese medicine. In addition, the outcome indicators have not been standardized and unified, and there is a lack of evidence on the long-term efficacy of Chinese patent medicine for TTH. This study is the first exploratory application of evidence maps to compare the characteristics and clinical research progress of 28 Chinese patent medicines for TTH, which can provide a reference for research on the optimization of Chinese medicine strategies for TTH.