Table 1. Suggestions to reduce publication bias^a, and examples of where each suggestion is being used and/or who has suggested/advocated the approach.

Suggestion	Definition (as given in the survey)	Studies/authors who have posited this method, or current examples
Mandatory publication	As part of gaining ethical approval and/or by law, researchers would have to guarantee publication of their research, regardless of the findings	Advocated by [17]; [10]
Negative results journals/articles	Having more journals specifically designed to accept research with negative, null and unfavourable results	[11,18,19]
Open reviewing	Requiring that journals name the reviewers and publish their comments with the final manuscript	[10,20]
Peer-review training and accreditation	Requiring all peer-reviewers to attend peer-review training after which they would become accredited peer-reviewers on a peer-review database, which can also highlight potential conflicts of interest	[9,10]
Post-publication review	Editors make a decision regarding the publication of an article. After publication, other researchers provide review comments which the authors can respond to. Although specific experts can be asked to conduct post-publication review, anyone is free to comment on all or part of the paper	[10,16,21]
Pre-study publication of methodology	Researchers publish full details of their planned methodology before commencing the research. The methods are then peer-reviewed to help ensure they are well justified. Once the study is completed, the full manuscript is peer-reviewed and published, regardless of the findings	[10,22]
Published rejection lists	Journals would openly archive the abstracts of rejected manuscripts with a summary of why the paper was rejected	[23]
Research registration	Researchers would be required to register their research on specific databases within a certain time frame of commencing the research. Registration would be compulsory for all research, and would include key aspects of the study design, including the primary and secondary outcomes and analysis plans	Advocated by [17], some ethics committees and required by some journals (e.g.[24])
Two-stage review	Authors initially submit only their introduction and methods to a journal. These get peer-reviewed, after which a decision is made regarding the study quality. If provisionally accepted, the authors would then submit the results and discussion for review. Rejection at this second stage would be justified by concerns over the quality of the reporting/interpreting of the results, but not according to the significance/direction of the results	[8,9,25–27]

^aThe suggestions and examples provided in this table are not extensive, but these ideas were the focus of this study