Learning from a retraction.

The publication and subsequent retraction1, 2 in June, 2020, of the Article Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis, based on an alleged dataset associated with Surgisphere, prompted us to examine The Lancet's peer-review processes to identify ways of further reducing risks of research and publication misconduct. As a result of this review, with immediate effect, we have made changes to the declarations we seek from authors, the data sharing statements we require for published research papers, and the peer-review process for similar papers based on large datasets or real-world data.

Changes to the signed declarations by authors in the author statements form will require that more than one author has directly accessed and verified the data reported in the manuscript. We will require that the authors who have accessed and verified underlying data are named in the contributors' statement. For research Articles that are the result of an academic and commercial partnership, one of the authors named as having accessed and verified data must be from the academic team. In addition, all authors will be asked to sign the author statements form to confirm they had full access to the data reported in their Article, and accept responsibility for submitting the Article for publication.

Journals that adhere to guidance from the International Committee of Medical Journal Editors require a data-sharing statement for papers that report results of a clinical trial. Lancet journals will now require all research papers, irrespective of method, to include a data-sharing statement that details what data will be shared, whether additional documents will be shared (eg, the study protocol), when data will become available, and by what access criteria data will be shared. Investigators should be aware that editors will take data-sharing statements into account when making editorial decisions.

All Lancet journals will now introduce additional peer-review requirements for papers based on large, real-world datasets. Editors will ensure that at least one peer reviewer is knowledgable about the details of the dataset being reported and can understand and comment on its strengths and limitations in relation to the research question being addressed. For studies that use very large datasets, editors will ensure that in addition to statistical peer review, a review from an expert in data science is obtained. Finally, we will explicitly ask reviewers if they have concerns about research integrity or publication ethics regarding the manuscript they are reviewing.

Throughout the COVID-19 pandemic the work of the research community in generating new knowledge has resulted in rapid advances in our understanding of severe acute respiratory syndrome coronavirus 2 and COVID-19. As trusted sources of information, the Lancet journals are committed to ensuring that our editorial processes will continue to be as robust as possible.