There may be little or no published clinical trial data available when a drug is new. There is a variation in opinion among drug bulletin editors on the use of unpublished information, such as company data on file, and incomplete information, such as that published only as abstracts. Reasons for avoiding unpublished information are that it has not been peer-reviewed, and cannot be independently assessed by the bulletin’s readers. However, this approach may miss important parts of the picture, because studies with positive results are more likely to be published than those with negative results (i.e. no efficacy and/or with more serious adverse effects).4 Whatever the policy of your bulletin, it is important that it is transparent so that your readers know the basis of the advice. Some bulletins give a precise description of the documents they used in preparing an article and how they obtained them. This is useful for the bulletin’s readers, and also to show those who may disagree with the recommendations of the article that the article is robust.