Chart assignment
Charts to read and discuss
Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.
Chart 1 of 1 · Clinical trials
How many clinical trials start each year?
The interactive chart needs JavaScript. The numbers are on the chart's page.
About 31,100 clinical trials registered on ClinicalTrials.gov started in 2025, up from about 11,900 in 2008 and 1,900 in 2000, the registry's first year. Early years count fewer trials because registering wasn't required until medical journals asked for it in 2005 and a U.S. law did in 2007; late registrations still add a few to recent years. ClinicalTrials.gov lists trials from around the world, not only the U.S.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: ClinicalTrials.gov (U.S. National Library of Medicine), counted with its API v2 (Public domain (U.S. government work); source National Library of Medicine) · Data as of Nov 3, 2026
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