The protocol is the master plan for a trial. It describes the objectives, design, methodology, statistical considerations and organisation of the study, and everyone running it must follow it.
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Clinical trial protocol
noun · clinical research
A document that describes the objectives, design, methodology, statistical considerations and organisation of a trial.
Related terms
In short
Explained
The widely used definition from ICH good clinical practice describes a protocol as a document that sets out the objective or objectives, design, methodology, statistical considerations and organisation of a trial, and it usually also gives the background and rationale. In ICH usage the word also covers its amendments. Check the current ICH E6 text for the exact wording and structure.
In practice a protocol reads as a long structured document. It starts with a title page and a one-page synopsis, then moves through background, objectives and endpoints, study design, eligibility, the intervention, the schedule of visits and procedures, safety monitoring and reporting, statistics, data handling, ethics and administration. Many sponsors follow templates, such as the SPIRIT checklist for trial protocols; see the SPIRIT checklist generator and the clinical trial protocol template.
Objectives say what the trial is trying to learn. Endpoints are the measurements that answer those questions; see clinical trial endpoints. The design section states the phase, the comparator, randomisation and blinding, and how long each participant is followed.
Inclusion and exclusion criteria define who can enrol. The schedule of assessments is the grid of visits against procedures (vital signs, labs, questionnaires, dosing). It is the part most directly turned into data collection, and the schedule of assessments builder shows how it maps to forms.
The safety section defines which adverse events are recorded, for how long, and how serious ones are escalated. The statistics section gives the analysis populations and the basis for the sample size. Data handling describes the source data, the CRFs and how quality is monitored.
protocol_v3.pdf
Draft study
Life of a protocol
A sponsor or investigator team writes the protocol, often starting from a synopsis and a template.
The sponsor signs off, and the ethics committee or IRB reviews it. Regulatory submission follows where required.
Visits, forms, eligibility checks and consent documents are built from the approved text.
Sites follow it. Departures are logged as protocol deviations; see protocol deviation tracking.
If the plan must change, a numbered amendment is approved and rolled out. See protocol amendments.
Upload a protocol in the free sandbox and let AI draft the visit schedule and forms for you to review. Nothing is saved without your approval.
In Capture
Capture's AI study builder reads a protocol in PDF, DOCX or DOC and drafts the visit schedule and forms. A person reviews every draft before anything is saved, and forms then move from draft to approved. A blank eCRF PDF (cover page, form index, visit-by-form matrix and every approved form) can be exported for ethics or IRB submission.
protocol_v3.pdf
Draft study
The document that describes the objectives, design, methodology, statistical considerations and organisation of a clinical trial. All sites and staff follow it.
The sponsor, or the lead investigator in an investigator-initiated trial, usually with statisticians, clinicians and operations staff contributing.
The synopsis is a short summary, typically a page or two, of the main design points. The protocol is the full controlling document.
A formal, numbered change to an approved protocol. It normally needs ethics committee approval, and regulatory review where required, before sites implement it.
A departure from the approved protocol, such as a missed assessment or an out-of-window visit. Deviations are recorded and assessed; some are classed as important.
No. The protocol gives the main statistical considerations; the statistical analysis plan is a separate, more detailed document written before analysis.
Keep exploring
How to write a clinical trial protocol
Step-by-step guide.
Protocol template
A structure to start from.
Protocol synopsis generator
Draft the one-page summary.
Protocol to study setup
AI-drafted build.
Clinical trial endpoints
What the protocol measures.
IRB
Who approves it.
Protocol amendments
Changing a live study.
Upload it in the free sandbox and review the AI draft. No credit card.