PROSPERO's systematic review protocols of traditional Chinese medicine for COVID-19: An overview

BACKGROUND: A large number of protocols for Systematic Reviews (SR) of Traditional Chinese Medicine (TCM) for coronavirus disease 2019 (COVID-19) have been registered in the International Prospective Register of Systematic Reviews (PROSPERO). This study aimed to analyze the innovativeness and rigorousness of the SR protocols and make recommendations for the design and implementation of future SRs on TCM for COVID-19. This effort is likely to enhance the value of the produced information and prevent the futility of the research. METHODS: PROSPERO was searched comprehensively for identifying SRs of TCM for COVID-19 from the inception of the database to August 2020. Two researchers independently screened the literature, extracted the data, and cross-checked the retrieved information for consistency. The following details were recorded: database, registration time, organizations, types of research included, participants, interventions, and outcome measures. All extracted data were analyzed by an overview. The “P - participants, I - interventions, C - controls, and O - outcomes (PICO)” included in the protocols were compared for similarity. The outcomes of the included SR protocols were compared with the newly published Core Outcome Sets (COSs). RESULTS: A total of 80 protocols of SR related to TCM for COVID-19 were obtained after a primary search, and finally 71 protocols were included. The majority of the protocols were from China. Thirty-two organizations participated in the protocol registrations, including 11 hospitals and 21 universities/colleges. However, some protocols were not innovative or rigorous enough, as the PICO of some protocols were similar and non-specific, and the searched literature was incomprehensive. In addition, COS is not commonly adopted. CONCLUSIONS: Registering a protocol of SR is an effective way to ensure the usefulness of the produced information, and to avoid the duplication of research and the wastage of resources. In future SR protocols, it is important to focus on and solve the methodological problems such as non-specific PICO, incomprehensive literature retrieval, and improper outcome measures.