About deltatrials

Our Mission

deltatrials is an open data platform that tracks how clinical trials change over time. We believe transparency in clinical research benefits everyone — patients, researchers, and the broader healthcare community.

Data Provenance

All clinical trial data is sourced from ClinicalTrials.gov, maintained by the U.S. National Library of Medicine. Our automated pipeline fetches updates daily, capturing any changes since the previous sync. Every version of every trial record is stored in full, giving us a complete audit trail.

The dataset covers 600,000+ clinical trials spanning decades of research — from early-phase safety studies to large-scale phase III efficacy trials.

How We're Different

Most clinical trial databases show you the current snapshot of a trial. deltatrials shows you the complete history. Using SCD2 (Slowly Changing Dimension Type 2) versioning, we capture every change — status transitions, protocol amendments, enrollment updates, contact changes, and more.

When a trial moves from Recruiting to Completed, we don't overwrite the old record. We close it and open a new version, preserving the exact state at each point in time. See our Methodology page for a deeper explanation.

About This Project

deltatrials is an independent project. We are not affiliated with the U.S. National Library of Medicine or any pharmaceutical company. Our goal is to make clinical trial data more accessible and transparent.

Data displayed on this site is for research and educational purposes only. It is not medical advice. See our Terms of Service for the full disclaimer.