The reporting quality, scientific rigor, and ethics of randomized placebo-controlled trials of traditional Chinese medicine compound formulations and the differences between Chinese and non-Chinese trials.

backgroundAn increasing number of randomized placebo-controlled trials involving traditional Chinese medicine (TCM) compound formulations have been implemented worldwide.

objectiveThe aim of this study was to assess the reporting quality, scientific rigor, and ethics of randomized placebo-controlled trials of TCM compound formulations and compare these differences between Chinese and non-Chinese trials.

methodsEnglish-language databases included the following: PubMed, OVID, EMBASE, and Science Citation Index Expanded. Chinese-language databases included the following: Chinese Biomedical Literature Database, Wanfang Database, Chinese Scientific and Technological Periodical Database, and the China National Knowledge Infrastructure. All were searched from respective inception to March 2009 to identify randomized placebo-controlled trials involving TCM compound prescriptions. Two reviewers independently assessed the retrieved trials via a modified Consolidated Standard of Reporting Trials (CONSORT) checklist and some evaluation indices that embodied the TCM characteristics or the scientific rigor and ethics of placebo-controlled trials. Trial publishing time was divided into 3 intervals: phase 1 (≤1999); phase 2 (2000-2004); and phase 3 (2005-2009). The number and percentage of trials reporting each item and the corresponding differences between Chinese (mainland China, Hong Kong, and Taiwan) and non-Chinese (eg, Japan, United States, Australia, Korea, and United Kingdom) trials were calculated. Moreover, the influence of trial publishing time on the reporting of CONSORT items and the differences in the number of items reported for each time interval between Chinese and non-Chinese trials were assessed.

resultsA total of 324 trials from China and 51 trials from other countries were included. A mean of 39.7% of the CONSORT items across all Chinese trials and 50.2% of the items across all non-Chinese trials were reported. The number of the reported CONSORT items all increased over time in both groups and the gap between Chinese articles and non-Chinese articles gradually decreased. Additionally, of the 324 Chinese articles, 137 (42.28%) reported TCM syndrome type, 113 (34.88%) reported the diagnostic criteria of diseases for TCM, and 69 (21.30%) reported efficacy evaluation indices of TCM. Of the non-Chinese articles, 3 (5.88%) reported TCM syndrome type and 1 (1.96%) reported the diagnostic criteria of diseases and evaluation indices of efficacy for TCM. It was found that 45.37% and 6.17% of Chinese articles reported the standard intervention for the diseases being treated and the emergency plan, respectively, compared with 23.53% and 9.80% for the non-Chinese articles; 33.02% and 10.49% of Chinese articles reported informed consent and ethics committee approval, respectively, compared with 92.16% and 82.35% for the non-Chinese articles. With regard to placebo ethics, 38.89% of the Chinese trials and 23.53% of the non-Chinese trials found it would not be ethically acceptable to use placebo alone in the control group.

conclusionsThe data indicate that the reporting quality of the included trials on TCM compounds has improved over time, but still remains poor regardless of Chinese or non-Chinese trials. Across all trials, particularly Chinese trials, the reporting of the CONSORT items was inadequate (39.7%). The difference in the mean number of the reported CONSORT items between Chinese trials and non-Chinese trials narrowed from phase 1 (10.0 vs 13.8) to phase 3 (14.4 vs 17.4). Moreover, a large number of trials, especially non-Chinese trials (94.1%), were lacking syndrome differentiation of TCM. More importantly, in many placebo-controlled trials, especially Chinese trials, the use of placebo was not justified and was ethically contradictory.