The Agency for Healthcare Research and Quality (AHRQ) defines a primary care practice-based research network (PBRN) as a group of practices devoted principally to the primary care of patients and affiliated with each other (and often with an academic or professional organization as well) to investigate questions related to community-based practice and to improve the quality of primary care. This definition includes the sense of an ongoing commitment to network activities and an organizational structure that transcends a single project.

It has been said that if you have seen one PBRN, you have seen one PBRN. This is because each is unique with regard to its mission, vision, purpose, and structure. Not all are based in primary care settings. Some are local, while others are regional; some are discipline-specific (e.g., family practice, dental), while others are geographically centered or serve various populations (e.g., underserved populations). A PBRN is a group of practices consisting of academic and community-based practices (either or both) devoted principally to the care of patients. PBRNs are often affiliated with each other (i.e., meta-networks), and frequently, they are affiliated with academic or professional organizations as well.

Many PBRNs have begun to envision their networks as places of learning, where clinicians are continually engaged in reflective inquiries about practice and where they and their patients in the community are united with science to search for answers that can provide a basis for improved delivery of primary care (Lindbloom et al. 2004). Others are devoted to improved patient outcomes and identifying and replicating best practices as it relates to their individual practice settings. The purpose of each PBRN is unique yet all are related to “real world” research in “real world” settings.

Lindbloom EJ, Ewigman BG, Hickner JM. Practice-based research networks: the laboratories of primary care research. Med Care 2004;42(4 suppl):III 45–9.

There are no steadfast rules with regard to what constitutes a PBRN. A PBRN is a group of clinicians or practice sites that collaborate to answer questions suited to their mission and purpose. . AHRQ, as a funding agency for primary care PBRNs, has set forth guidelines for PBRNs seeking grant support through its agency. It recognizes a primary care PBRN organizational structure only if it includes a core of at least 15 practices and/or 15 clinicians devoted to the primary care of patients. Many PBRNs have started with less, but they were not eligible for recognition by AHRQ as a primary care PBRN.

  • Purpose and Mission Statement. Each network has an accepted statement of its purpose and a mission that includes an ongoing commitment to the research endeavor.
  • Staff. At a minimum, each network should have a Network Director and at least one dedicated staff member. The director is typically responsible for most administrative, financial, and planning functions for the network.
  • Mechanism for Community Feedback. A mechanism should be in place for obtaining advice and feedback from the patient communities served by the network.
  • Communication Structure. Each PBRN should have an organizational structure that transcends a single study, including multiple systems of communication with and among participating practices in the form of regularly produced newsletters, e-mails or list serves, conference calls, and/or face-to-face meetings of various combinations of network members.

For the past 30 years, primary care PBRNs have engaged in the scientific research within the patient care or practice setting. There are more than 200 PBRNs in the United States, and the numbers are growing. A list of the registry for primary care PBRNs can be found at

A major goal of primary care PBRNs, some of which have existed in the United States for more than 20 years, has been to involve busy community-based clinicians and their staff in activities directed by investigators experienced in clinical and health services research. Most are within primary care settings, although PBRNs may be in subspecialty areas, inpatient or other settings, disease state–specific communities (e.g., HIV, Parkinson’s disease), or special study populations (e.g., underserved, rural). Leaders of PBRNs in the United States and other countries have also recognized the potential of primary care networks to expand their purposes beyond traditional research to the nurturing of an evidence-based culture in primary care practice (Thomas et al. 2001).

Thomas P, Griffiths F, Kai J, O'Dwyer A. Networks of research in primary health care. BMJ 2001;322:588–90.

Typically, PBRNs draw on the experience and insight of practicing clinicians to identify and frame research questions whose answers can improve the practice of primary care.

By linking these questions with rigorous research methods, the PBRN can produce research findings that are immediately relevant to the clinician and that, in theory, are more easily translated into practice. The best of PBRN investigative efforts have linked relevant clinical questions with rigorous research methods in community settings and have produced scientific information that is not only externally valid, but, in theory, also easily assimilated into everyday practice (Nutting et al. 1999).

Nutting PA, Beasley JW, Werner JJ. Practice-based research networks answer primary care questions. JAMA 1999;37:1092–104.

There are more than 200 PBRNs within the country. AHRQ invites all interested primary care networks to register with the AHRQ PBRN Resource Center (PBRN RC). The PBRN RC provides resources and assistance to primary care PBRNs engaged in clinical and health services research. The PBRN RC provides support to registered PBRNs through various methods, such as leading a series of Web-based seminars and offering technical assistance in research methodology and PBRN organization and development. A list of the registry can be found at

At this time, there are several regional and local pharmacy PBRNs. The numbers are growing. Like the AHRQ-registered primary care PBRNs, they may be serving special populations or specific disease states, or they may be primary care, institutional by nature. Others have evolved around community pharmacy, and a few exist within health systems. Currently, no formal registry for pharmacy PBRNs exists, although some are registered with AHRQ at the link above.

Information obtained from the Inventory and Evaluation of Clinical Research Networks (IECRN) provides good insight into the PBRN industry. The IECRN project is a component of the National Institutes of Health (NIH) Roadmap. The NIH Roadmap’s primary goal is accelerating medical discovery to improve health. Common “lessons learned” across multiple outcome areas, as shared by the Best Practices Study, Final Report, July 28, 2006, include those at the following site: