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Enabling implementation studies

The Los Angeles Data Resource (LADR) is a joint project of major Los Angeles healthcare provider organizations aimed at enabling implementation studies as well as patient-oriented research collaborations.

LADR enables investigators to assess how many patients at each participating institution match the criteria for studies they are planning.

The resulting counts of potentially eligible patients can then be used to foster research partnerships with co-investigators at the most appropriate sites. Data on individual patients can only be obtained after further approvals from each institution that chooses to participate in the proposed study.

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Who is Participating?

Current LADR consortium members are:

  • UCLA
  • Cedars-Sinai Health System
  • City of Hope
  • USC
  • Children's Hospital Los Angeles
  • Charles R. Drew University

  * CHLA and CDU count information pending

What data is available through this tool?

Cohort counts rather than data sets are available through LADR. These are based on de-identified data extracted from each institution’s clinical data warehouse, transformed into a common data representation, and stored in a separate, dedicated data repository at each institution. LADR currently allows for interactive searches based on patients':

  • Demographic characteristics (e.g. age, sex, race-ethnicity)
  • Encounter diagnoses (ICD-9 & ICD-10)
  • Laboratory test results
  • Medications prescribed
  • Procedures (CPT, ICD-9 & ICD-10)
  • Vital signs and vital status

What can LADR not do?

LADR is a cohort discovery tool, meaning only patient counts can be retrieved. Individual patient-level data cannot be accessed through this tool, but it is possible to gather this information outside of LADR. Please contact us directly at if you would like individual patient-level data. These requests will be reviewed on a case-by-case basis.

Who can use the tool?

To access LADR at UCLA, researchers must be affiliated with a UCLA principal investigator and complete training. 
If you don't have an account with LADR, please email

Additional Resources

Training materials and background information about LADR are available on the LADR website.


Data is obtained from administrative records and electronic health records of patients that received care across the affiliated medical centers.

The time range in which data is available varies by the institution and depends on the institution’s EHR database. LADR is continually being updated on a weekly or monthly basis, depending on the institution. We will display a chart with data counts across the institutions in the near future.

There is currently no option for patients to request that his/her information be excluded from the LADR database, but all of the fields for every patient specified by HIPAA rules for safe harbor de-identification will be excluded from the data repository except for dates and zip codes.

More information on the source data can be found on the LADR website.

ICD codes are based on billing data from both inpatient and outpatient encounters.

We have integrated both inpatient and outpatient medications using the Anatomical Therapeutic Chemical (ATC) Classification System hierarchy.

Yes, each patient reported in LADR is unique to the corresponding institution. Whether a query consists of multiple ICD-9 codes, demographics, date restrictions, etc., each patient is only counted once.

Currently, if a patient has been admitted to more than one LADR-affiliated site, he/she will be counted as a separate patient at each institution. This may inflate the total patient count across all institutions, but the site-level count will remain unaffected.


LADR is a cohort discovery tool and, thus, will only provide patient counts for a specific query. To go further and receive identified patient data for recruitment purposes, you will need to follow the steps below:

Obtain patient counts from each of the sites using LADR. Recruit co-investigators at each site from which you would like to receive identified patient data. Obtain IRB approval from each institution from which you would like to receive identified patient data. If applicable, the other LADR sites can use Trust and Rely to expedite their IRB approval process. Each site will then obtain the list of patients from their respective CTSI to recruit patients.

To get more information on how to access patient-level data from LADR, please click on the link below:

Obtaining Medical Record Data to Conduct Your Research

Our next step in LADR is to perform more in-depth data quality checks comparing the data available through all of the participating institutions. However, please report any query results that appear inaccurate so we can investigate right away.

Release Notes

Version-Release: May 2016


A web browser is required to use LADR. The following four browsers are currently supported:

  • Mozilla Firefox
  • Microsoft Internet Explorer
  • Apple Safari
  • Google Chrome

Please note that JavaScript must be enabled on your web browser.

Temporal Queries

The Temporal Query Tool extends the query functionalities provided by the classic Query Tool. Users can now define a sequence of events using time-based relationships to further add to their query criteria. For more details regarding the Temporal Query Tool, you can review the LADR Tutorial Video at the 8:19 mark.