Study protocol

Study protocol articles will generally only be considered for proposed or ongoing trials that have not completed participant recruitment at the time of submission. Trials advises that study protocols are submitted well before recruitment completes, however, we will also, on occasion, consider study protocols submitted well before the last patient/last visit. In such cases, the expected last patient/last visit date and an explanation of why it was not possible to submit earlier, should be included within the manuscript text. Please confirm the status of your study at submission.

Trials also considers study protocols assessing aspects of the design, conduct or reporting of randomized trials. These studies do not necessarily need to be trials and include studies such as core outcome set development for use in trials and process evaluations that run alongside trials. Please follow the relevant reporting guideline for the study design and include the corresponding checklist as an additional file.

All submitted protocols must have ethical approval. If the study has undergone full external peer review as part of the funding process, the study protocol will usually only undergo editorial peer review by a Protocol Editor. Study protocols without major external funding will undergo full, external peer review. Study protocols without ethical approval will generally not be considered. To support efficient handling of your study protocol, the Editors advise that prospective authors familiarize themselves with this Editorial on what is expected in a study protocol submission.

Trials welcomes public and patient co-authors. Where a study explicitly mentions patient or public involvement in the design, delivery or dissemination of the study, we would anticipate that there would be at least one patient or public co-author.

Please note: From 1st January 2021, Trials will no longer consider study protocols for pilot or feasibility trials for publication. We recommend that these manuscripts are instead submitted to our sister journal, Pilot and Feasibility Studies.

Statistical Analysis Plans can be directly integrated into the study protocol being submitted for publication (for uncomplicated RCTs this might be sufficient) or included as an additional file to the submission. For more information, read our Editorial: Prospective reporting of statistical analysis plans for randomised controlled trials. Standalone statistical analysis plans submitted separately to a study protocol should be submitted as an Update. These should be submitted before data lock.

Additional Files

On submission, the following documentation should be uploaded as Additional Files. If the original documents are not in English, an English translation of each is mandatory.

SPIRIT Guidance

Study protocols reporting a clinical trial can be formatted for submission to Trials in two ways:

  1. By following the guidance set out in our structured study protocol template. This is the preferred option if you have not yet started writing your manuscript.
  2. By submitting a populated SPIRIT checklist and SPIRIT figure alongside your manuscript. The SPIRIT checklist can be downloaded here or completed using this online tool: www.goodreports.org/reporting-checklists/spirit/. The figure must be included in the main body of the text and the checklist must be provided as an additional file. Both the figure and the checklist should be referenced in the text. If any of these elements are missing from the submission, or if the SPIRIT checklist is incomplete (i.e. missing page and line numbers, or a short explanation why an item is not applicable next to each SPIRIT item), the manuscript will be returned to the authors.

All study protocols for clinical trials are reviewed by a Protocol Editor to ensure that they adhere to our SPIRIT guidance. Please ensure this guidance is followed carefully to prevent delays to the peer review process. For further advice on compliance with the recommendations of the SPIRIT statement, please see: The SPIRIT Checklist—lessons from the experience of SPIRIT protocol editors.

It is understood that for some study protocols certain aspects may not comply fully with each item of the SPIRIT Statement. If used, the checklist will not be used as a tool for judging the suitability of manuscripts for publication in Trials, but is intended as an aid for authors to clearly, completely, and transparently let reviewers and readers know what authors intend to do. Where an item is not applicable, authors can state this but must also add a brief explanation as to why the item is not applicable. Eg. Biological Specimens, Item no. 33: Not applicable, no samples collected. Simply saying ’N/A’ will lead to the manuscript being returned. Likewise, if the structured protocol template is used, please follow the guidance by leaving all headings, identifiers and curly brackets in the order given and provide a complete response under each. A complete example can be found here.

The online protocol template called SEPTRE (SPIRIT Electronic Protocol Tool & Resource) is also a web-based option to create, manage, and register protocols using the SPIRIT guidance.

In Review

Authors submitting to Trials can now opt-in to a service called In Review, which provides a pre-print service, meaning the article can be shared with funders and others in a citeable way while it is under review. It also provides authors with on-demand information on the status of their manuscript, enables them to share their work with funders and others, and allows their wider community to comment and collaborate - all whilst their manuscript is under review. Please see here for full details.

Preparing your manuscript

The information below details the section headings that you should include in your manuscript and what information should be within each section.

Please note that your manuscript must include a 'Declarations' section including all of the subheadings (please see below for more information).

Title page

The title page should: