Results Summary

PCORI funded the development of PCORnet®, the National Patient-Centered Clinical Research Network, to make it easier and more efficient to conduct research. PCORnet is made up of Partner Networks that harness the power of large amounts of health data and patient partnerships.

Clinical Data Research Networks (CDRNs) are one type of network supported by PCORI. CDRNs consist of two or more healthcare systems, including hospitals, integrated delivery systems, and federally qualified health centers. Each CDRN transforms data gathered from routine patient care across its participating health systems to a consistent format, the Common Data Model (CDM), to enable rapid response to research-related questions.

PCORI funded PaTH Towards a Learning Health System’s (PaTH) participation in PCORnet from 2015 to 2019. This report outlines PaTH’s achievements in building its research infrastructure capacity to

  1. Create ways to involve patients, healthcare providers, health plans, and health systems in the research process and decision making about the network
  2. Continue building the PCORnet CDM to add new types of data, ensure data quality, answer questions and requests, link to data outside the network, and keep data secure and private
  3. Create an efficient infrastructure to carry out clinical trials
  4. Create rules and guidance to protect people who take part in research studies, keep participants’ information confidential, and examine the risks of proposed studies
  5. Work with PCORnet partners and partners outside the network to do research studies, build information systems, and share knowledge and practices
  6. Create a plan to fund the network after PCORI funding ends

Network at a glance

Led by the University of Pittsburgh, PaTH was made up of seven additional health systems serving eight states. The network used electronic health records, or EHRs, from its partners to conduct research projects that aimed to help healthcare providers and patients make better health decisions. The network focused on diverse research areas but had a special emphasis on healthy lifestyles and weight; a type of lung disease; and a type of irregular heartbeat that can lead to stroke or heart failure. Data are available on more than 13 million patients.

TitlePaTH Towards a Learning Health System (PaTH)
Network designClinical Data Research Network (CDRN)
Lead partnerUniversity of Pittsburgh
Other partnersGeisinger Health System
Johns Hopkins Health System
Johns Hopkins University
Lewis Katz School of Medicine at Temple University
Michigan Medicine
Ohio State University
Ohio State University Wexner Medical Center
Penn State College of Medicine
Penn State Health Milton S. Hershey Medical Center
Temple Health System
University of Michigan
University of Pittsburgh Medical Center
UPMC Health Plan
PopulationOver 13 million patients in the New England, Mid-Atlantic, and midwestern regions served by a partner organization
Area(s) of focusHealthy lifestyles and weight, idiopathic pulmonary fibrosis, and atrial fibrillation

How does the network operate?

PaTH’s executive committee was made up of three lead researchers, two patients, a technology lead, and a data lead. The University of Pittsburg coordinated network activities and led the healthy lifestyles and weight research group. Penn State oversaw the lung disease research group. John Hopkins led the heart research group. It also served as the main Institutional Review Board (IRB), which made sure studies were ethnical and protected participants. Temple University oversaw a PCORnet CDM group.

PaTH signed data use agreements with all partners. Network partners stored patient data securely. To answer research questions, the network provided data that cannot be used to identify patients and followed strict security rules.

How did the network involve patients and other partners?

Two patients had voting rights on the executive committee. The network also worked with healthcare providers at partner sites known as clinical champions. These champions helped make it easier for people working in healthcare settings to be in research studies. A network committee involved people from partner IRBs and the community to make sure that any research conducted focused on the patient. PaTH developed surveys for patients to get their opinions on research. Network members created easy-to-read summaries for patients of published studies that used PaTH data.

The network developed a story booth project where patients and caregivers shared their experiences about health and the healthcare system. People who participated could be matched with researchers leading studies on the same topic to form research teams where patients help guide the research. The story booth project worked with Patient-Powered Research Networks (PPRNs) and other community-based patient organizations to help patients and caregivers share their stories.

A stakeholder engagement work group oversaw these engagement activities.

Who is in the network?

The network had data on more than 13 million patients as of July 30, 2019. Data sources included Medicare insurance claims, EHRs, and relevant laboratory results and data on whether patients lived in rural, urban, or suburban areas. PaTH also had data from surveys patients filled out during their healthcare visits or as part of research surveys. Some partners had private insurance claims data. PaTH formatted EHR data about weight, lung function, and heart health to fit the CDM. Data are available since at least 2011, and prior to 2011 for most sites.

Population (as of 07/30/19)


  • 70% white
  • 17% other
  • 13% black
  • 4% Hispanic


  • 56% female
  • 44% male


  • 16% 17 years or younger
  • 33% 18–44 years
  • 25% 45–64 years
  • 25% 65 years or older

How is the network supporting research?

While a Partner Network in PCORnet, PaTH participated in 15 studies.

How does the network support future research?

PaTH follows PCORI standards to make sure their networks continue after PCORI’s funding ends. CDRNs format their data to the Common Data Model and involve patients and healthcare providers in planning and carrying out research studies. CDRNs also take part in research with other networks in PCORnet and build relationships outside of PCORnet. PaTH developed a process by which informatics experts and clinical researchers engage research teams to help them develop projects within PCORnet and a payment system to fund the network. PaTH also works with diverse stakeholders across the country to create a website on patient stories and build research teams that include patients and caregivers and provide them with tools to support engagement.


Clinical Data Research Networks (CDRN): CDRNs are networks that originate in healthcare systems, such as hospitals, health plans, or practice-based networks, and securely collect health information during the routine course of patient care.

Common Data Model (CDM): A CDM establishes a standard way of defining and formatting data.

Institutional Review Board (IRB): A group that follows federal regulations, state laws, and institutional policy to review, monitor, and approve research in order to protect the ethical rights and privacy of the subjects involved.

PCORnet: PCORnet is a network of networks that brings together patients, clinicians, researchers, and healthcare systems to share information and participate in research.

Project Information

Kathleen McTigue, MD, MPH^
University of Pittsburgh
A PaTH Towards a Learning Health System (PaTH)

Key Dates

July 2019

Study Registration Information

^Rachel Hess, MD, MS, at the University of Pittsburgh was the principal investigator for Phase I of this project.


Has Results
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: April 18, 2024