Background: Randomized controlled trials (RCTs) which are of poor quality tend to exaggerate the effect estimate and lead to wrong or misleading conclusions. The aim of this study is to assess the quality of randomization methods, allocation concealment and blinding within traditional Chinese medicine (TCM) RCTs, discuss issues identified for current TCM RCTs, and provide suggestions for quality improvement.
Methods: We searched Chinese Biomedical Database (CBM, 1978 to July 31, 2009) and the Cochrane Library (Issue 2, 2009) to collect TCM systematic reviews and meta-analyses according to inclusion/exclusion criteria, from which RCTs could be identified. The quality assessment involved whether the randomization methods, allocation concealment and blinding were adequate or not based the study reported. Stratified analyses were conducted of different types of diseases published in different journals (both Chinese and foreign) using different interventions. SPSS 15.0 software was used for statistic analyses.
Results: A total of 3159 RCTs were included, of which 2580 were published in Chinese journals and 579 in foreign journals. There were 381 (12%) RCTs which used adequate randomization methods; 207 (7%) RCTs which used adequate allocation concealment and 601 (19%) which used adequate blinding; there were 130 (4%) RCTs which both used adequate randomization methods and allocation concealment; and there were only 100 (3%) RCTs which used adequate randomization methods, allocation concealment, as well as blinding. In the RCTs published in foreign journals, the adequate randomization methods, allocation concealment and blinding accounted for a relatively large proportion (25%, 26%, and 60%, respectively) and increased with years, while in the RCTs published in Chinese journals, only the adequate randomization methods improved over time. The quality of non-drug intervention (chiefly acupuncture) RCTs was higher than that of drug intervention RCTs. In drug intervention, the quality of listed drugs is higher than the others. The quality of all included RCTs of all types of diseases was generally poor and no studies that were large in size and of high quality were found.
Conclusion: The quality of the current TCM RCTs as judged by their publications is generally poor, especially those published in Chinese journals. In future, researchers of TCM RCTs should attach more importance to experimental design and methodological quality, receive relevant training, and improve reporting quality using the Consolidated Standards of Reporting Trials (CONSORT) statement, so as to improve the quality of TCM clinical research and ensure truth and reliability of conclusions.