[Characteristics analysis of oral clinical trials registered in Chinese Clinical Trial Registry]

Objective: To investigate the project characteristics of oral clinical trials registered in Chinese Clinical Trial Registry (ChiCTR), and to provide reference for medical institutions to improve the quality of oral clinical trials and formulate management systems. Methods: The ChiCTR database was retrieved to collect all the oral-related clinical trials from the time of database establishment to July 25, 2021. Those clinical trials were analyzed statistically in respect of name of registered project, registration time, registration status, regional distribution of research institutions, approval status by ethics committee, sample size, source of funds, involved disease, research type and design, randomization method, and whether blind method was adopted. Results: A total of 778 oral clinical trials, which studied mainly in the oral and maxillofacial diseases, periodontal tissue diseases, oral implant diseases, oral mucosal diseases, and oral prosthetic diseases, were retrieved in the database. Beijing, Sichuan, Shanghai, Guangdong and Hubei were major regions where oral clinical trials were carried out, accounting for 69.68% (772/1 108) of the total. The top four funding sources were hospital finance [24.93% (186/746)], local government finance [22.39% (167/746)], self-financing [17.69% (132/746)], and national finance [12.47% (93/746)]. For the types of researches, 520 interventional studies and 244 observational studies were identified (accounting for 66.84% and 31.36%, respectively). The research designs were dominated by ways of randomized control (381, 48.97%), of which 240 (62.99%) trials were with missing or unspecified blinding methods. Conclusions: Oral clinical trials are increasing year by year, but they are regionally imbalanced, and still need to be further improved in registration information and research design. Administrative departments should pay more attention to strengthen the publicity and education on the registration and publication mechanism of clinical trials, and enhance researchers' cognitions in clinical trials registration and clinical trials design.