The project is a reaction to under-reporting of research. A substantial proportion (estimates range from one-third to one-half) of medical research goes unpublished. It has also been shown that negative findings are
less likely to be published than positive ones, even in the absence of conflicts of interest. Much medical research is done by the pharmaceutical industry, which have a
conflict of interest reporting results which may hurt sales of their products. There is a measurable
funding bias in reporting; studies have shown that published drug studies funded by pharmaceutical companies are much more likely to support the use of the tested drug than studies with other funding. Industry-funded trials are also less likely to be published. If the statistical methods used to analyse the trial are not chosen before the study it started, there is a danger that researchers will intentionally or unintentionally pick the method that gives the results they expect, or which gives the most significant results. This makes the analysis
statistically invalid. Not publishing trials which fail to find a clear effect exposes trial volunteers to pointless risk and wastes research effort (as the same trial is repeated over and over). It also biases the medical literature, making it report effects where none exist (since, given enough trials, eventually one will find a difference by pure chance).
Pre-trial registration makes non-publication and changes in analysis methods obvious to medical reviewers. It also enables authors of meta-studies to track down and analyse missing data. Finally, it lets doctors and patients know when a trial is looking for volunteers. ==Coverage==