> ## Documentation Index
> Fetch the complete documentation index at: https://glossary.micahealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Observational study

A research study where researchers observe and track participants' health outcomes without assigning specific treatments. Instead of controlling who gets which treatment, researchers monitor natural groups or outcomes. A patient registry is one example of this type of study.

## Related terms

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[*Source*](https://clinicaltrials.gov/study-basics/glossary)