Increasing numbers of PCORI draft final research reports will be utilizing the PCORnet distributed data network as a component of their research. The amount of utilization of the PCORnet network will vary from project to project, depending on study design and methods. The use of PCORnet data and tools can range from extensive engagement in many aspects of the work, such as a secondary data analysis of weight loss after bariatric surgery, to only modest involvement when the network is used, for example, to consistently identify potential participants for a trial but not with other aspects of the trial such as outcome data collection. Consistent description of the network is important so that readers know the provenance of the data, the ongoing quality checks, and the methods used.

The following text is approved for use in DFRRs and must be included in any DFRR in which the PCORnet distributed data network is used. Depending on how extensive the utilization of the PCORnet resources are, the description could be as short as a paragraph or as long as a page, with references to the appropriate publications. The text could also be in a short appendix and referred to in the text:

The research reported in this final research report was conducted using PCORnet®, the National Patient-Centered Clinical Research Network. PCORnet has been developed with funding from the Patient-Centered Outcomes Research Institute® (PCORI®).

PCORI funded the development of PCORnet® to address an urgent national need—capacity to conduct patient-centered outcomes research faster, more efficiently, and at lower cost, by leveraging the power of health data, reusable research infrastructure, and unique patient partnerships. PCORnet addresses several challenges of traditional clinical research, including the time and expense involved in developing a study, the lack of data on certain rare conditions or underserved populations, data quality concerns, and the recognition that many studies don’t answer the questions most important to patients.

Development of PCORnet began in 2014.[1] The network is composed of a Coordinating Center, nine Clinical Research Networks (CRNs), two Health Plan Research Networks (HPRNs), and patient partners. Each CRN is made up of multiple health care delivery systems, including hospitals, primary care and specialty practices, and safety net clinics. The HPRNs are currently composed of two large U.S. health plans. PCORnet Network Partners (i.e., CRNs and HPRNs) work to capture complete, longitudinal healthcare data on their patient populations, including EHR data generated by patient care in the delivery system, and claims information or other records representing care received outside the delivery system. This provides the ability to research care and outcomes in multiple diverse clinical settings over time. Patient partners are members of PCORnet’s governance, participate on its committees, and provide valued input and leadership in all facets of the development and execution of research efforts. Standing and template data use agreements among the participating entities facilitate timely conduct of research.

PCORnet is a distributed research network utilizing harmonized data. In a distributed network, health information stays at the institution that generated the data through patient care. Information is transferred from the electronic health record system into the institution’s data warehouse where structured patient data are transformed into the PCORnet Common Data Model (CDM). In this way institution-specific information, such as vital signs, demographics, laboratory test results, or care utilization, is harmonized so that data have a common format to facilitate data aggregation and analysis.[2] Through data harmonization, differences in data format related to the version or type of electronic health record are addressed. The distributed model is designed to keep patient data secure. The entire process is performed locally at the network site, and aggregate deidentified results are returned to the PCORnet Coordinating Center. The data remains at the network site behind institutional firewalls, maintaining security. The demographics of the individuals in the databases are broadly representative of the US population. All activities are conducted with the governance of data use agreements, HIPAA, and human subjects review boards (IRB).

The PCORnet Coordinating Center is responsible for maintaining and updating the PCORnet CDM, as well as for the development and enhancement of distributed data query tools. These tools facilitate extraction of information to conduct secondary data analyses as well as identify individuals who might be candidates for recruitment as participants in research studies such as cohort studies and clinical trials.

Assessment of the quality and completeness of the data used by PCORnet Network Partners is conducted on a regular basis. Data harmonization and transformation into the PCORnet CDM at the participating sites occurs every 3 months. The PCORnet Coordinating Center conducts quarterly data quality assessments of the participating Network Partners. These detailed evaluations assess for completeness and appropriate mapping to the PCORnet CDM or to standard reference terminologies such as LOINC for laboratory data or ICD10 for diagnoses, as well as other assessments.[3] Additional information regarding the structure and process of the PCORnet distributed research model can be found at and in related publications.[4]


Posted: April 28, 2021

[1] Fleurence RL, Curtis LH, Califf RM, Platt R, Selby JV, Brown JS. Launching PCORnet, a national patient-centered clinical research network. J Am Med Inform Assoc. 2014;21(4):578-582.

[2] PCORnet. PCORnet Common Data Model. 2019; common-model/. Accessed April 16, 2020.

[3] Qualls LG, Phillips TA, Hammill BG, et al. Evaluating foundational data quality in the National Patient-Centered Clinical Research Network (PCORnet®). EGEMS (Wash DC). 2018;6(1):3.

[4] Forrest CB, McTigue KM, Hernandez AF et al. PCORnet 2020: current state, accomplishments, and future directions. J Clin Epid 2020; doi:

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