There is a growing need for secondary use of regularly collected health care information in research to develop scientific evidence and assist providers, patients, and policy makers to make informed decisions about clinical effectiveness, comparative effectiveness, population health, and outcomes. A distributed research network based on common data model, efficient processes, and infrastructure to analyze collected data will support these needs and address knowledge gaps. Tufts CTSI, in collaboration with Tufts Medical Center and Maine Medical Center, is developing a multi-institutional clinical research data network (CDRN) to support multi-site clinical research.

The Tufts CTSI Informatics team develops and maintains the Clinical Academic Research Enterprise Trust (CLARET) data warehouse. We are converting CLARET to an Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM) developed and maintained by the Observational Health Data Science and Informatics (OHDSI) community.


  • The OMOP Common Data Model allows for the systematic analysis of disparate observational databases.
  • Data standardization increases the potential for collaborative research.
  • Data from various sources are transformed into a common format and common representation.
  • Standard analytic methodss are applied to a common format for data quality, data characterization, safety surveillance, and other applications.

We continue to enhance the data warehouse to advance cohort discovery, recruitment planning, and retrospective and prospective clinical and translational research.

Clinical Research Data Network (CRDN)

In collaboration with Tufts Medical Center, Maine Medical Center, and other partners, Tufts CTSI is developing a multi-institutional clinical research data network (CRDN) to support multi-site clinical research. The design and open source distribution of the OMOP CDM infrastructure makes network participation more attractive to community-based hospitals. Our use of the OMOP CDM is supported by the growing set of tools and capabilities of the OHDSI consortium for transforming, characterizing, and analyzing disparate data sources. The Tufts CTSI CRDN will enable federated cohort discovery and facilitate research.

Resources and Services

  • Cohort discovery to identify study populations is offered at no cost, available only to Tufts Medical Center researchers. This service provides the researcher with an aggregated count of patients matching inclusion/exclusion criteria. Currently, CLARET does not allow researchers to directly query data: the Informatics team is available to assist. Please follow IRB guidelines and obtain the necessary approvals or waivers.
  • Federated cohort discovery to identify study populations across Tufts CTSI CRDN participating sites is offered at no cost to Tufts Medical Center researchers and researchers from partner institutions needing to assess the feasibility of conducting a multi-site study. This service provides researchers with an aggregated count of patients matching inclusion/exclusion criteria. Please follow the IRB guidelines for your institution and obtain necessary approvals or waivers.
  • Limited data set (LDS) to identify specific patients based on study criteria and extracts fully de-identified or limited patient-level datasets for clinical research projects. IRB approval specifically outlining data needs, purpose, and use is required. Our Informatics team will execute queries and return results to users (as approved by their IRB protocols).

Who is eligible?

CLARET is currently available only to Tufts Medical Center researchers to request and receive aggregated counts of potential participants. Availability of other services is limited at this time.

For fast and successful service:

  • Please follow IRB guidelines in the HIPAA forms section and obtain necessary approvals or waivers.
  • You must have a valid IRB approval which describes whether you are allowed to access de-identified or anonymized datasets and how these data will be stored.
  • Please complete a data use agreement (DUA) with Tufts Medical Center. A sample DUA (Word document) is available here.
  • You must have established a HIPAA-compliant system or have secure access to a HIPAA-compliant system to store extracted data. Please follow the IRB Confidentiality and Data Security Guidelines for Electronic Research data, available here.
  • You must have already received a related aggregated patient count report (cohort discovery) to be able to request an LDS.

Please note:

If you plan on collecting data for the purpose of human subjects research, your project must be reviewed and approved by your Institutional Review Board (IRB).

Tufts CTSI does not provide data storage for any exported datasets. You must ensure you have a plan to transfer and store any exported report or data to your own system, and ensure this system meets the HIPAA requirements of Tufts Medical Center.

Learn about Research Electronic Data Capture (REDCap).