Selection of best randomized controlled trials of Japanese Kampo medicines: Introduction of the trials and the hardships in their conduction

Abstract Background More than 500 randomized controlled trials (RCTs) were selected from various databases by the evidence‐based medicine committee of the Japan Society for Oriental Medicine (JSOM). Their structured abstracts have been published in Japanese and English in “Evidence Reports of Kampo Treatment.” Methods From among these RCTs, “Kampo Best RCTs” were selected according to impact factor and number of Google Scholar citations. Results Four of the authors in this article presented their data at a symposium at the 74th Congress of the JSOM in June 2024. Kazunari Tominaga was elected as the No. 1 author among the best RCTs. His two articles described the effects of rikkunshito on functional dyspepsia and non‐erosive gastroesophageal reflux disease, respectively. Hidekazu Suzuki was elected as No. 2. His article described the effect of rikkunshito on functional dyspepsia. The No. 3 author, Toshimi Kaido, and No. 4 author, Chu Matsuda, described the effects of daikenchuto on adult gastrointestinal disorder following liver transplant and the effects of hangeshashinto on chemotherapy‐induced stomatitis, respectively. These four articles were all based on double‐blind RCTs. Although a range of hardships were encountered during the studies, these RCTs were reported in original articles, providing clinical evidence of high international reputation. Conclusion Here, we describe the details and the hardships encountered by the authors, identify points to note in the interpretation of clinical trial results, and finally mention the current status and future prospects of Kampo RCTs.