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Tools for Cohort Selection

Stanford’s cohort selection tools can help you identify and quantify potential participants listed in Stanford’s electronic medical records system.

We’re also members of several collaborations where Stanford researchers can search for co-investigators and patient participants at other research institutions.

Stanford Medicine Tools

The STAnford Research Repository, or STARR, is Stanford Medicine's approved resource for working with clinical data for research purposes. STARR is the home of two web-based tools, Cohort Discovery and Chart Review. These cohort selection tools are only available to authorized Stanford researchers.

Cohort Discovery Tool

The Cohort Discovery Tool is an online search dashboard that enables researchers to quickly assess whether there are enough Stanford patients that meet the enrollment criteria to justify a specific study. The tool can access structured data such as diagnosis and procedure codes, drug classes and ingredients, and more. It also includes unstructured clinical notes and time-based filtering parameters. Visualization features allow for comparisons segmented by sex, age, race, and location.

Chart Review Tool

The Chart Review Tool is designed to facilitate a deeper review of patient charts. Its powerful search engine enables an investigator to gain insights into target patients and their medical histories to further refine a research proposal.

Multi-site Tools

The Trial Innovation Network (TIN)

This NIH-funded collaborative enables Stanford researchers to submit study proposals to designated contacts at participating research institutions to quickly identify potential partners for multi-site studies.

Accrual to Clinical Trials (ACT) Network

This NIH-funded multi-site cohort exploration network allows Stanford researchers to remotely search deidentified patient records at other institutions to identify potential research participants and co-investigators at multiple sites.


This University of California-Stanford collaboration is working to share best practices that improve the cost, efficiency, and effectiveness of study participant recruitment approaches across California.

To access any of the above multi-site cohort selection tools, email EngageParticipants@stanford.edu to set up a consultation.