The Consistency between Registered Acupuncture-Moxibustion Clinical Studies and Their Published Studies and Update Status of Registered Information

Background: Few studies have analyzed the consistency between registered acupuncture-moxibustion clinical studies and their published research results as well as their update status of registered information. Methods: We searched for acupuncture-moxibustion clinical studies that were registered at the World Health Organization International Clinical Trials Registry Platform between 2013 and 2015 and collected data regarding their characteristics and update status. Published results of these registered studies were identified and compared with registered information. Results: A total of 425 registered acupuncture-moxibustion clinical studies were included; 379 (89.2%) of them were interventional studies, and the remaining 46 (10.8%) were observational studies. Forty-six studies (10.8%) were found to have published results, and 51 published articles were identified. Overall, 73.2% (311) of registered studies did not update the research status in time; 46.6% (198) stopped updating before recruiting; 21.6% (92) stopped updating after recruiting; and 4.9% (21) stopped updating after completion. Regarding the 46 studies with published results, 29 (63.0%) were considered to be affected by reporting bias. These reporting biases predominantly involved the omission of some predefined outcomes or endpoints (16 studies), contradictions regarding descriptions of sample sizes (9 studies), discrepancies in treatment measurements or group distribution (7 studies), and inconsistent treatment durations (4 studies). When compared with other studies, significant and various reporting biases could also be commonly found in fields other than acupuncture-moxibustion. Conclusions: There were many discrepancies between registered information and published reports on acupuncture-moxibustion, which could also be commonly observed in other fields. Moreover, a large proportion of registered studies did not update their research status in time. Efforts should be made to improve the reporting quality and timely updates.