Purplelink
← Why it matters

Manuscript red-team reference · companion to Paper Review

trial not registered

Clinical claim without a registry entry.

What it is

Most major medical journals (NEJM, JAMA, Lancet, BMJ) require clinical trials to be registered prospectively in a public registry — ClinicalTrials.gov, ISRCTN, EU-CTR — with the primary endpoint specified before enrollment. The point is to prevent outcome switching: registering 5 outcomes, finding 1 significant, and reporting only that one as the primary finding.

Why a reviewer cares

Reviewers look for: a registration number on the paper; whether the registered primary endpoint matches the reported primary endpoint; whether registration was prospective (before enrollment) or retrospective (after, which doesn't count). Mismatches are a major red flag.

How to fix it

Register the trial prospectively, name the primary endpoint, and stick to it. If the analysis plan changed during the trial, document the change with a date and rationale in the methods. Cite the registration ID prominently in the manuscript abstract.


This is one of ~15 canonical methodology explainers Paper Review's red-team report links to. To get a full review of your manuscript, start a Paper Review — $5.