Cross-sectional studies on traditional Chinese medicine (TCM-CSs) have become the most published type of TCM observational study; however, the research scope of current TCM-CSs is unknown. A scoping review of the literature was performed. A descriptive approach to summarize the core study characteristics was prepared, along with structured tables and figures to identify salient points of similarities and differences noted across studies. The reporting quality of TCM-CSs was assessed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) cross-sectional checklist. Eight databases (Embase, CENTRAL, MEDLINE, AMED, CBM, CNKI, WanFang, and VIP) were systematically searched for TCM-CSs published up until 20 January 2020. The literature screening and evaluating were independently conducted by two researchers. When there was disagreement, a third-party senior researcher made the judgment. A total of 198 TCM-CSs published between 1997 and 2019 were included, 160 English studies and 38 Chinese studies, respectively. More TCM-CSs were published in each successive year. The journal Evidence-Based Complementary and Alternative Medicine published more TCM-CSs (24) than any other journal. Most TCM-CSs were conducted in mainland China (81, 40.9%), followed by Taiwan, China (44, 22.2%) and HKSAR, China (19, 9.6%). The most commonly used sampling method was purposive sampling (94, 47.5%), following by convenience sampling (60, 30.3%). The research topics can be summarized in four major categories as follows: constitution-related research (11.1%), TCM pattern-related research (18.7%), TCM intervention-related research (55.1%), and others (15.6%). The average sufficient reporting rate of included TCM-CSs according to the STROBE cross-sectional checklist was 45.6%. Papers written in English reported 9 items (items 2, 4, 14a, 16a, 18, 19, 20, 21, and 22) more frequently than papers written in Chinese. The number of TCM-CSs is increasing. Research topics are diverse; however, the reporting quality is unsatisfactory. In particular, TCM-CSs need greater transparency and standardization.
Keywords: Cross-Sectional Studies; Reporting Quality; Review; Scoping Review; Traditional Chinese Medicine.