Jump to page content

Reporting of retrospective registration in clinical trial publications

Prospective registration of clinical trials is an important practice to reduce biases in their conduct and reporting. However, the enforcement of ethical and legal mandates for prospective registration are handled inconsistently: only some registries mark retrospectively registered registrations as such, and, while International Committee of Medical Journals Editors (ICMJE) – journals in principle mandate prospective registration, there are concerns that this principle is not always enforced. It is therefore often not easily discernible from the public information whether good reporting practices were followed.


In this project, we investigate how authors report retrospective registration in trial results publications.


The project is based on the IntoValue 1 and 2 projects. We screen all results publications of clinical trials conducted in Germany between 2009 and 2017 with a registry entry in ClinicalTrials.gov or the Deutsches Register Klinischer Studien (DRKS; German WHO primary trial registry), that were registered retrospectively, for reporting and explanations of retrospective registration. We also investigate factors associated with retrospective registration and reporting thereof.


A key feature of trial registration is the prespecification of a study’s aims and hypotheses, which is undermined by retrospective registration. By quantifying and exploring this issue, we aim to raise standards of registration practices.


Martin Haslberger, MSc

Research fellow