Clinical Trial Registration and Data Sharing

Clinical Medicine and Pharmacology requires transparent prospective registration of clinical trials so that readers can distinguish the planned study from decisions made after results became known. Registration, ethics review, reporting of outcomes and a data sharing statement are separate obligations. Satisfying one does not excuse omission of the others.

Studies requiring registration

A clinical trial prospectively assigns people or groups to a health related intervention to evaluate its effects on health outcomes. The intervention may involve a medicine, device, procedure, behavioural programme, prevention strategy or change in delivery of care. Nonrandomised assignment does not by itself remove the registration requirement. Authors unsure whether their study meets the definition should seek advice before recruitment rather than rely on the manuscript’s eventual label.

Timing and acceptable register

The trial must be registered in an appropriate publicly accessible register accepted by ICMJE, such as a WHO primary registry or ClinicalTrials.gov, at or before the first participant gives consent to enrol. The manuscript reports the registry, identifier and registration date. For timing, CMP uses the first submission of registration materials to the registry and examines any substantial posting delay. The record must include the required 24 data fields with meaningful information and be publicly accessible. An institutional project number or ethics approval number is not a substitute for a public trial registration.

Accuracy changes and late registration

Registration should identify the planned population, interventions, outcomes and other required information. Authors keep the record current and disclose changes to outcomes, sample size or analysis plans with their timing and reasons. The report explains discrepancies between the registry, protocol and manuscript. A retrospectively registered trial must be explicitly identified as such and the delay explained; late registration does not become prospective merely because it precedes manuscript submission. Exceptional editorial consideration cannot be promised and must be justified transparently.

Reporting the trial

Authors provide the protocol and relevant amendments, describe recruitment and allocation, and use CONSORT 2025 and applicable extensions for randomised trials. They report the prespecified primary and secondary outcomes, important harms and deviations from the plan. Exploratory analyses are labelled. Registration alone does not establish adequate methods or ethical conduct, and a favourable result does not cure missing safeguards. A submitted trial protocol follows SPIRIT 2025 and identifies its version and amendment history; a protocol article is not presented as a completed trial report.

Data sharing statement in the article

A clinical trial report includes a data sharing statement stating whether deidentified individual participant data and data dictionaries will be shared; which data and accompanying documents will be available; when and for how long they will be available; and the criteria, access route and conditions for obtaining them. A statement that data will not be shared must be explicit; an undecided answer is insufficient. The journal’s requirement for a statement does not mean that identifiable participant records must be publicly posted.

Plan in the registration record

Trials beginning enrolment on or after 1 January 2019 must include a data sharing plan in their registration, in accordance with ICMJE recommendations. If that plan changes, authors update the record and explain the change in the article’s statement. They should ensure that participant consent and governance arrangements support the promised access. A plan, a published statement and actual delivery of data are distinct stages, and the authors remain accountable for representing each accurately.

Editorial checks and follow up

Editors compare the report with the registration and may request clarification or independent advice. Unexplained discrepancies, concealment of a trial or an inaccessible registration can prevent assessment and may trigger integrity review. Readers who find material inconsistencies or an unfulfilled access promise may report them to CMP with the article and registry identifiers. Questions or supporting documents should be sent through the CMP editorial office at cmpeditorialoffice@jandoopress.com, identifying the manuscript number or article DOI where available.

Last updated: 17 September 2026