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Clinical and Translational Science Center

Clinical and Translational Science Center


Multi-campus inquiries determine clinical trial feasibilty

Nothing will bring an idea for a clinical study to a screeching halt faster than a shortage of potential research subjects. What options does an investigator have? A new multi-campus patient inquiry tool can help resolve such a stalemate.

UC Research eXchange (UC ReX) Data Explorer is a tool that allows researchers to query the aggregate databases of the five medical campuses at UC Davis, Irvine, Los Angeles, San Diego and San Francisco. Using a secure, web-based drag-and-drop interface, Data Explorer identifies the number of patients who meet the inclusion and exclusion criteria specified in the query.

UC ReX is a component of the University of California Biomedical Research Acceleration, Integration and Development (UC BRAID) program that links research activities across the five UC medical campuses – all recipients of a Clinical and Translational Science Award. According to Nick Anderson, director of informatics research for the UC Davis School of Medicine, UC ReX enables researchers to search de-identified records for more than 12 million patients on the UC medical campuses. Search criteria include demographics, diagnosis and procedure codes (ICD-9 and CPT), top 150+ lab orders, and an evolving set of prescribed medications.

“UC ReX Data Explorer generates an aggregate numeric count of patients matching query criteria at each local integrated data warehouse. Using those data, researchers can take steps to establish research permission for identifying individual potential research participants,” Anderson explained. “The strength of Data Explorer is its capacity to explore a very large and heterogeneous patient population directly from the desktop, and through this process, develop preliminary data for clinical research design.”

Without Data Explorer, researchers would have to define, gain approval, and run individual queries at each of the five data warehouses separately, a time-consuming and cumbersome process. Using Data Explorer, investigators can isolate cohorts by medical characteristics and estimate the incidence of rare diseases across California. The result is an ability to expand a study from a single to multi-site proposal and to assess the feasibility of creating targeted enrollments, such as the number of potentially eligible patients by gender, race and ethnicity.

“Researchers can use Data Explorer to structure queries that identify, for example, all African American females 55 to 75 years of age who have been diagnosed with diabetes and cardiovascular disease and have been discharged to a hospice-care setting,” Anderson said. “Data Explorer is a dynamic hypothesis-generation tool that can perform a broad range of analytics that researchers would never before have been able to accomplish so economically and efficiently.”

Because the output is simply the de-identified number of potential subjects who match query criteria, the process does not constitute actual research, and no prior Institutional Review Board (IRB) review or patient consent procedure is necessary to perform such queries. Researchers then can use the results to determine which of the other UC medical centers may be in a position to participate in a collaborative study.

Clinical and teaching faculty members, research fellows, medical residents and students are eligible to use Data Explorer, and training sessions are readily available.

“Data Explorer has unparalleled capabilities for population-level data discovery across an enormous aggregate of data, while also creating a path for development of closer collaborations among clinical and translational research throughout the UC system. It is a highly unique system that can assist in moving an investigator quickly from a discovery process to the design and conduct of actual clinical research,” Anderson said. “Any investigator who wants access to Data Explorer can begin by contacting us through the CTSC.” § 

Visit on the web to learn more. Some of the information for this article was adapted from the Data Explorer pages of other UC campuses.

Five steps from query to recruitment

1.  Obtain patient counts from all five UC sites using UC ReX.

2.  Recruit co-investigators at each site from where you want to access data using research networking tools, such as DIRECT2Experts, if needed.

3.  Obtain UC Davis IRB approval if requested research data includes identified datasets.

4.  If applicable, the other UC sites can use Trust and Rely to expedite their IRB approval process.

5.  Work with your co-investigator(s) to obtain the list of patients you want to recruit at each of the UC medical centers.

UC Rex Data Explorer: Access and training

For more information or to register for training, visit the UC Davis Data Explorer web page:

To request help or submit questions, send an e-mail to