Data sharing

Sharing the full data sets underlying the results in your article brings many benefits. It enables reuse, reduces research waste, and promotes collaboration. Greater transparency increases trust in research results by allowing results to be independently verified. These benefits lead to a more reliable evidence base and a healthier world.

BMJ do not consider the deposition of data, including clinical trial data, in recognised repositories to be prior publication.

Many funders now require that the data sets from the studies they fund be shared. A list of research funders that mandate data archiving is provided by SHERPA/JULIET.

 
BMJ data sharing policy

All BMJ journals require a Data Availability Statement for any submitted research articles. The requirements for data sharing is dependent on the policy the Journal adopts.

BMJ has three policies on data sharing:

Tier 1:

      • We require that the data generated by your research that supports your article be made openly and publicly available upon publication of your article. Where it is not possible or viable to make data openly available (due to confidentiality or sensitivity issues), they should be shared through a controlled access repository.

Tier 2: 

      • We strongly encourage that data generated by your research that supports your article be made available as soon as possible, wherever legally and ethically possible
      • We require data from clinical trials to be made available upon reasonable request
      • We require that a data sharing plan must be included with trial registration for clinical trials that begin enrolling participants on or after 1st January 2019. Changes to the plan must be noted in the Data Availability Statement and updated in the registry record (to comply with ICMJE recommendations)

Tier 3: 

      • We strongly encourage that data generated by your research that supports your article be made available as soon as possible, wherever legally and ethically possible.

Information about what policy each BMJ Journal adopts can be found on this table.

 
Data Availability Statement

All BMJ Journals require a Data Availability Statement for any submitted research articles. On submission, authors are asked to select at least one of the standardised Data Availability Statements text options below in bold as applicable and to supplement these statements with additional information as noted in the guidance below. Authors can select more than one statement if they have data under different conditions. The ICMJE recommendations provide further guidance on how to compose a rich statement.

These statements will be published under the header ‘Data Availability Statement’ within the footnotes section of the final published article.

    • Data are available in a public, open access repository
      Please state the repository name, the persistent URL, and any conditions of reuse (eg. licence, embargo). All data that are publicly available and used in the writing of an article should be cited in the text and the reference list, whether they are data generated by the author(s) or by other researchers.
    • Data are available upon reasonable request
      Please state what the data are (e.g. deidentified participant data), who the data are available from, their publishable contact details (e.g. a generic lab email address or an individual’s ORCID identifier – please ensure you have permission) and under what conditions reuse is permitted. Is there additional information available (e.g. protocols, statistical analysis plans)?
    • Data may be obtained from a third party and are not publicly available
      Please state what the data are (e.g. deidentified participant data), who the data are available from, their publishable contact details (e.g. a generic lab email address or an individual’s ORCID identifier – please ensure you have permission), and under what conditions reuse is permitted. Is there additional information available (e.g. protocols, statistical analysis plans)
    • All data relevant to the study are included in the article or uploaded as supplementary information
      Please ensure this does not include patient identifiable data. Please state ‘Not applicable’ in the free text box
    • Data sharing not applicable as no datasets generated and/or analysed for this study
      Please state ‘Not applicable’ in the free text box
    • No data are available
      Please state ‘Not applicable’ in the free text box

 
How to cite data

All data that are publicly available and used in the writing of an article should be cited in the text and the reference list – whether they are data generated by the author(s) or by other researchers.

Data citations should include author(s), title, data repository, the document version (e.g. most recent date modified), the Digital Object Identifier (DOI) and should follow BMJ reference style.

Add [dataset] as a prefix immediately before the reference, so we can properly identify it as a data reference; this identifier will not appear in the published article.

Example:
[dataset] [52] Wang G, Zhu Z, Cui S, Wang J. Data from: Glucocorticoid induces incoordination between glutamatergic and GABAergic neurons in the amygdala. Dryad Digital Repository, August 11, 2017. https://doi.org/10.5061/dryad.k9q7h

 
How to share data

For clinical data (Individual Participant Data) we request that you use controlled access repositories, such as clinicalstudydatarequest.com, the YODA project, or Vivli. Please see this article for current practical guidance on clinical trial data sharing.

For pre-clinical data we recommend using recognised subject-specific repositories, such as GenBank, where relevant and available.

There are also a number of recognised, general repositories in which to deposit data, for example, DRYAD, OSF, FigShare and Zenodo. FAIRsharing and re3data.org provide a curated list of repositories.

 
What data should be shared

We encourage you to make available as much of the underlying data from your article as possible (without compromising participant privacy), but at least the minimum data required to reproduce the results presented in the associated article.

We consider any files generated by your research as constituting relevant data. This may be raw or processed data. Examples include (but are not limited to):

    • Individual-level deidentified patient data
    • Survey results
    • Interview transcripts
    • Statistical code
    • Images
    • Videos
    • Spreadsheets
    • Audio files
    • Text files
    • Imaging and scan files

To enable reuse and enhance reproducibility, all data should be shared using the sources file in which they were originally generated, for example:

    • Images should be provided as .png, .jpg, .eps, etc.
    • Text files should be provided as .txt, .doc, .rft, etc.
    • Spreadsheets should be provided as .csv, .xls, .tsv, etc.
    • Videos should be provided as .mp4, .avi, .wav, etc.
    • Imaging and scan files should be provided in .img, .dcm, hdr, etc.

Data should not be shared in any way that could compromise participant anonymity or privacy, and data should not be shared if that would require the authors to break any laws or licensing agreements. If the data used were licensed from a third party, the data availability statement should explain how to obtain a licence for that data.

Where a research community in a particular field has established standards for what, where, and how data should be shared, we expect authors to meet those.

While data sharing is not mandatory in most of our journals, BMJ reserves the right to request at any time confidential access to any primary data needed to reproduce the article so that the results reported can be verified. Editors may also use data availability statements to inform their editorial decisions.

 
Data from clinical trials

Where required, reports of clinical trials must include a commitment to make relevant anonymised patient-level data available on reasonable request (see this editorial in The BMJ for further explanation). This policy applies to any research article that reports the outcomes of a clinical trial of any type of intervention.

The International Committee of Medical Journal Editors (ICMJE) requires that clinical trials that begin enrolling participants on or after 1 January 2019 must include a data sharing plan in the trial’s registration. We encourage all authors to follow this best practice, however this is compulsory on The BMJ. The ICMJE’s policy regarding trial registration is explained here<. Read more at BMJ 2017;357:j2372.

 
How to access data that is available upon request

Data requesters should do the following:

 

    • Email the corresponding author for the paper to request the relevant data.
    • For requests to The BMJ, a Rapid Response must also be submitted to the article. (Please see The BMJ’s specific instructions)
    • Provide the authors of the article a detailed protocol for the proposed study, and to supply information about the funding and resources you have to carry out the study.
    • If appropriate, invite the original author[s] to participate in the re-analysis.
    • If a month elapses without a response from the authors, please email the editorial office of the relevant journal.
    • The journal will assess the request and if appropriate will encourage the authors or their institution to share the data, although BMJ are not in a position to compel data release or broker agreements.