PubMed is the National Library of Medicine's platform for searching MEDLINE.
PubMed has a special search feature called Clinical Queries.
Within Clinical Queries, 5 clinical study category filters are available
- Therapy
- Clinical Prediction Guides
- Diagnosis
- Etiology
- Prognosis
Clinical Queries also allows you to choose a broad or narrow scope depending on your search needs.
For details about the Clinical Queries filters, see: