In traditional Chinese medicine (TCM) syndrome diagnosis research, the Delphi technique is often used to build expert consensus when evidence is limited and opinions differ. Despite its frequent use, there has been no systematic evaluation of how this method is conducted or reported in this context. This study investigates the consistency of Delphi method application and evaluates the quality of reporting in TCM research. A cross-sectional analysis was performed to identify studies utilizing the Delphi approach in TCM syndrome diagnosis. Searches were conducted in PubMed, Web of Science, CNKI, VIP, Wanfang, and SinoMed for publications in English or Chinese up to March 25, 2023. A structured extraction form captured study characteristics and methodological details to assess rigor and transparency. From 1832 screened records, 50 studies were included. The median panel size was 30 (IQR 20–34.5), with only 24% having diverse panel composition. Two Delphi rounds were most frequent (74%), followed by three rounds (14%), and only a quarter of studies predetermined the number of rounds. Key reporting elements were inconsistently documented: anonymity was mentioned in 18%, controlled feedback in 30%, process duration (mean 7.14 ± 3.29 months) in 20%, and predefined consensus criteria in 26% of studies. The use of the Delphi method in TCM syndrome diagnosis research shows considerable variation and often lacks transparent reporting. Developing standardized guidelines is crucial to enhance methodological consistency and reporting quality in future studies.
