The protocol is the trial’s blueprint — the single document that says exactly what will be done, to whom, how and why. Examiners love one distinction in particular: the difference between a protocol deviation and a protocol violation. Get that right and you’ve answered most of this topic.
Definition
Per GCP 1.44, the protocol is “a document that describes the objectives, design, methodology, statistical considerations and organisation of a trial,” together with its background and rationale. It is the trial’s blueprint — signed by the sponsor and investigator and approved by the EC and regulator before the trial begins.
Contents of a protocol (GCP 6)
- General information — title, protocol number, sponsor, investigators, sites.
- Background, rationale and objectives.
- Trial design — type, endpoints (primary/secondary), randomisation and blinding.
- Selection of subjects — inclusion / exclusion / withdrawal criteria.
- Treatment — investigational product, dosing, concomitant medication.
- Assessment of efficacy and safety; statistics (sample size, analysis, ITT).
- Direct access to source data; quality control; ethics; data handling; financing and insurance; publication policy.
Protocol amendment
An amendment is any written change to the protocol. It needs EC and regulatory approval before implementation — with one exception: a change made to eliminate an immediate hazard to subjects may be implemented first and reported afterwards.
Deviation vs violation
| Feature | Deviation | Violation |
|---|---|---|
| Severity | Minor / unintentional departure | Major / serious departure |
| Impact | No significant effect on subject rights/safety or data | Affects subject rights/safety/well-being or data integrity |
| Examples | Missed visit; out-of-window assessment; minor procedure miss | Enrolling an ineligible subject; dosing error; consent not obtained |
| Action | Documented | Documented + reported to EC / sponsor; the subject may be stopped |
Exam tip: protocol = blueprint (objectives, design, methods, statistics, organisation). An amendment needs EC + regulator approval before implementation — except to remove an immediate hazard. Deviation = minor, no impact, documented; violation = major, affects safety/data, documented and reported to EC & sponsor.
Think of the protocol as a contract the whole team signs up to. Small, harmless slips are deviations you simply record; anything that touches a subject’s safety or the integrity of the data is a violation you must escalate. That single line of reasoning carries the long essay, the short note and the viva.