Content area


Sharing clinical trial data: a proposal from the International Committee of Medical Journal Editors

Darren B. Taichman1, Joyce Backus2, Christopher Baethge3, Howard Bauchner4, Peter W. de Leeuw5, Jeffrey M. Drazen6, John Fletcher7, Frank A. Frizelle8, Trish Groves9, Abraham Haileamlak10, Astrid James11, Christine Laine12, Larry Peiperl13, Anja Pinborg14, Peush Sahni15 & Sinan Wu16 1) Annals of Internal Medicine2) National Library of Medicine3) Deutches Ärzteblatt (German Medical Journal)4) JAMA and the JAMA Network5) Nederlands Tijdschrift voor Geneeskunde (The Dutch Medical Journal)6) New England Journal of Medicine7) Canadian Medical Association Journal8) New Zealand Medical Journal9) BMJ10) Ethiopian Journal of Health Sciences11) The Lancet12) Annals of Internal Medicine13) PLOS Medicine14) Ugeskrift for Læger (Danish Medical Journal)15) World Association of Medical Editors16) Chinese Medical Journal

The International Committee of Medical Journal Editors

(ICMJE) believes that there is an ethical obligation to responsibly

share data generated by interventional clinical

trials because participants have put themselves at risk.

In a growing consensus, many funders around the world

– foundations, government agencies, and industry – now

mandate data sharing. Here we outline ICMJE’s proposed

requirements to help meet this obligation. We encourage

feedback on the proposed requirements. Anyone

can provide feedback at by 18 April


The ICMJE defines a clinical trial as any research

project that prospectively assigns people or a group of

people to an intervention, with or without concurrent

comparison or control groups, to study the cause-andeffect

relationship between a health-related intervention

and a health outcome. Further details may be found

in the Recommendations for the Conduct, Reporting,

Editing and Publication of Scholarly Work in Medical

Journals at

As a condition of consideration for publication of a

clinical trial report in our member journals, the ICMJE

proposes to require authors to share with others the

deidentified individual-patient data (IPD) underlying the

results presented in the article (including tables, figures,

and appendices or supplementary material) no later

than six months after publication. The data underlying

the results are defined as the IPD required to reproduce

the article’s findings, including necessary metadata. This

requirement will go into effect for clinical trials that begin

to enroll participants beginning one year after the

ICMJE adopts its data-sharing requirements*.

Enabling responsible data sharing is a major endeavor

that will affect the fabric of how clinical trials are

planned and conducted and how their data are used. By

changing the requirements of the manuscripts we will

consider for publication in our journals, editors can help

foster this endeavor. As editors, our direct influence is

logically, and practically, limited to those data underpinning

the results and analyses we publish in our journals.

The ICMJE also proposes to require that authors include

a plan for data sharing as a component of clinical

trial registration. This plan must include where the researchers

will house the data and, if not in a public repository,

the mechanism by which they will provide

others access to the data, as well as other data-sharing

plan elements outlined in the 2015 Institute of Medicine

report (e.g., whether data will be freely available to anyone

upon request or only after application to and approval

by a learned intermediary, whether a data use

agreement will be required) [1]. has

added an element to its registration platform to collect

data-sharing plans. We encourage other trial registries

to similarly incorporate mechanisms for the registration

of data-sharing plans. Trialists who want to publish in

ICMJE member journals (or nonmember journals that

choose to follow these recommendations) should

choose a registry that includes a data-sharing plan element

as a specified registry item or allows for its entry as

a free-text statement in a miscellaneous registry field. As

a condition of consideration for publication in our member

journals, authors will be required to include a description

of the data-sharing plan in the submitted


Authors may choose to share the deidentified

IPD underlying the results presented in the article

under less restrictive, but not more restrictive, conditions

than were indicated in the registered data-sharing


ICMJE already requires the prospective registration

of all clinical trials prior to enrollment of the first participant.

This requirement aims, in part, to prevent selective

publication and selective reporting of research outcomes,

and to prevent unnecessary duplication of

research effort. Including a commitment to a data-sharing

plan is a logical addition to trial registration that will

further each of these goals. Prospective trial registration

currently includes documenting the planned primary

and major secondary end points to be assessed, which

enables identification of incomplete reporting as well as

post hoc analyses. Declaring the plan for sharing data

prior to their collection will further enhance transparency

in the conduct and reporting of clinical trials by exposing

when data availability following trial completion

differs from prior commitments.

Sharing clinical trial data, including deidentified IPD,

requires planning to ensure appropriate ethics committee or institutional review board approval and the informed

consent of study participants. Accordingly, we

will defer these requirements for one year to allow investigators,

trial sponsors, and regulatory bodies time to

plan for their implementation.

Just as the confidentiality of trial participants must

be protected (through the deidentification of IPD), and

the needs of those reasonably requesting data met

(through the provision of useable data), the reasonable

rights of investigators and trial sponsors must also be

protected. ICMJE proposes the following to safeguard

these rights. First, ICMJE editors will not consider the

deposition of data in a registry to constitute prior publication.

Second, authors of secondary analyses using

these shared data must attest that their use was in accordance

with the terms (if any) agreed to upon their receipt.

Third, they must reference the source of the data

using a unique identifier of a clinical trial’s data set to

provide appropriate credit to those who generated it

and allow searching for the studies it has supported.

Fourth, authors of secondary analyses must explain

completely how theirs differ from previous analyses.

In addition, those who generate and then share clinical

trial data sets deserve substantial credit for their efforts.

Those using data collected by others should seek collaboration

with those who collected the data. However,

because collaboration will not always be possible, practical,

or desired, an alternative means of providing appropriate

credit needs to be developed and recognized

in the academic community. We welcome ideas about

how to provide such credit.

Data sharing is a shared responsibility. Editors of individual

journals can help foster data sharing by changing

the requirements of the manuscripts they will consider

for publication in their journals. Funders and

sponsors of clinical trials are in a position to support and

ensure adherence to IPD sharing obligations. If journal

editors become aware that IPD sharing obligations are

not being met, they may choose to request additional

information; to publish an expression of concern; to notify

the sponsors, funders, or institutions; or in certain

cases, to retract the publication.

In the rare situation in which compliance with these

requirements is impossible, editors may consider authors’

requests for exceptions. If an exception is made,

the reason(s) must be explained in the publication.

Sharing data will increase confidence and trust in

the conclusions drawn from clinical trials. It will enable

the independent confirmation of results, an essential

tenet of the scientific process. It will foster the development

and testing of new hypotheses. Done well, sharing

clinical trial data should also make progress more efficient

by making the most of what may be learned from

each trial and by avoiding unwarranted repetition. It will

help to fulfill our moral obligation to study participants,

and we believe it will benefit patients, investigators,

sponsors, and society.

Feedback may be posted at by 18

April 2016.

*) The ICMJE plans to adopt data-sharing requirements after considering

feedback received to the proposals made here.


This editorial is being published simultaneously in Annals of Internal

Medicine, British Medical Journal, Canadian Medical Association Journal,

Chinese Medical

Journal, Deutsches Ärzteblatt (German Medical Journal),

Ethiopian Journal of Health Sciences, JAMA (Journal of the American

Medical Association), Nederlands Tijdschrift voor Geneeskunde (The

Dutch Medical Journal), New England Journal of Medicine, New Zealand

Medical Journal, PLOS Medicine, Revista Médica de Chile, The Lancet,

and Ugeskrift for Læger (Danish Medical Journal).

Bib ref: 
Dan Med J 2016;63(2):A5205


1. Institute of Medicine. Sharing clinical trial data: maximizing benefits, minimizing risk. Washington, DC: National Academies Press, 2015.


Add new comment