China has made considerable strides as a research base and cost-effective location for clinical trials in recent years, but national standards of trial reporting still have a long way to go, a new analysis suggests.

In a paper published online by BioMed Central, researchers led by Dalu Zhang from the Department of Public Health and Epidemiology at the UK’s University of Birmingham undertook a systematic review of randomised controlled trials (RCTs) performed in China and published during 2004.

Zhang et al used or adapted a subset of indicators from CONSORT (Consolidated Standards of Reporting Trials) to assess the quality both of reporting in the Chinese trials and, where relevant information was available, of the actual study conduct. The CONSORT statement was originally developed in the mid-1990s by an international group of clinical trialists, statisticians, epidemiologists and biomedical editors with the goal of improving reporting standards in RCTs.

The results of the analysis were largely discouraging. For example, among 307 papers selected, nearly two thirds (199 or 64.8%) failed to report methods of randomisation while 254 (82.4%) did not mention blinding of either participants or investigators.

The reporting of baseline characteristics, primary outcome and length of follow-up was found to inadequate in a substantial proportion of studies. Only 89 or 29% of the RCTs included in the analysis fully reported the baseline characteristics of the participants in a separate table.

Just 11 or 3.6% indicated the measure used as the primary outcome. The remainder “merely reported an ordered list of results from which it was not possible to distinguish which outcome was the primary”, the researchers noted. In 105 (34.2%) of the papers assessed, there was no information about the length of follow-up.

Fewer than 11% of the RCTs reported having ethical committee approval, even though this is a legal requirement in China. And only 17.4% of the studies gave adequate details about informed consent procedures – “a few mentioned that participants attended ‘of their own free will’ but the remainder made no mention of consent”, Zhang et al commented. Nonetheless, “this level appears better than in a recent review of traditional Chinese medicine trials”, they added.

On the upside, 53.7% of the trials reviewed stated that none of the participants dropped out, while more than 60% reported a drop-out rate of less than 5% and two-thirds a rate of less than 10%. In countries with more established research programmes, a drop-out rate of below 5% “is generally considered a very good result”, the researchers pointed out.

Reporting of randomised controlled trials in China “requires substantial improvement to meet the targets of the consort statement”, they concluded. While the conduct of Chinese RCTs cannot be inferred directly from the standard of reporting, “without good reporting the methods of the trials cannot be clearly ascertained”, the researchers warned.