Evidence-appraisal glossary
Registry study
An observational study built on a registry, a structured collection of data on people who share a given disease, exposure, device, or procedure. Patients are observed as they are treated rather than assigned to groups at random.
Also called: patient registry, disease registry.
Registries aim to capture large, representative populations over long periods, which makes them valuable for tracking rare events, long-term safety, and real-world patterns of care. Because treatment is not randomized, comparisons between groups are vulnerable to confounding, and conclusions depend heavily on how complete and accurate the recorded data are. A registry describes what happens in practice well but points to cause only cautiously, and only with careful statistical adjustment.
This is a plain-language methodology definition for reading research. It is general education, not medical advice.