Non publication trial is a more serious problem in China than in other countries.
Regulatory submission, trial publication, trial registration, and systematic review produce unstructured datasets that are insufficient for supporting evidence-based decision making.
A data extraction form was designed previously, and included the following items: general identification information (authors, title, journal, date of publication, protocol name, and duplication of publication), trial, type of patients, intervention characteristics, and reported outcomes.
Covariates that were selected to be analyzed in the Bayesian network meta-analysis, a priori, included patient performance status, years of publication, trial sample size and the proportion of stage IV disease versus locally advanced.
Despite considerable recent efforts to implement measures to reduce the non-publication of trials, publication bias is still a major problem in medical research.
Risk assessments were performed using data from a number of sources (as available) including trial primary publications, trial design manuscript, trial protocol, and trial presentations.
We assessed differences in the statistical plan for model adjustment between the trial protocol and the trial publication for those trials with available protocols.
Overall, there is a strong impression of publication of trials whose results favoured agomelatine and the non-publication of less favourable trials (although Servier's willingness to provide us with all data relating to trials of agomelatine should be noted).
Because of publication bias, trials on CAM modalities may not be found on routine literature searches.
