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Emergency Medicine Network (EMNet)


In 1996, 12 emergency physicians created the Multicenter Airway Research Collaboration (MARC) to examine emergency asthma care. Multicenter studies were needed since some of the most pressing research questions require hundreds, even thousands, of patients to have adequate statistical power. Without several years of patient enrollment, such sample sizes are beyond the reach of most individual institutions. According to plan, MARC investigators completed several observational studies before they launched their first multicenter randomized trial in 1998. During these early years, the number of MARC investigators grew to almost 80 sites and the group expanded their research into other types of pulmonary/allergy emergencies.

In 2001, the collaboration further expanded its research agenda to include public health issues. In light of this much broader mission, MARC was renamed the Emergency Medicine Network (EMNet). Today, EMNet focuses on three areas:

  1. Respiratory/allergy emergencies -- Multicenter Airway Research Collaboration (MARC),
  2. Health policy -- e.g., National ED Inventories (NEDI), National ED Safety Study (NEDSS), and
  3. Other public health projects -- e.g., ED 24-hour Research Network (ED24), surveys, analysis of federal datasets.

Many of these activities are described below. EMNet also is involved in several affiliated projects.

Multicenter Airway Research Collaboration (MARC)

MARC continues to be a key program within EMNet. The collaboration works on many “airway” disorders, including asthma, chronic obstructive pulmonary disease (COPD), anaphylaxis, pneumonia, and bronchiolitis. Multicenter studies of longer duration (e.g., weeks to months) are the core activity of this program.

The network has now completed over 30 MARC studies. Recent multicenter MARC studies have included: a chart review study of ED visits for food allergy, a randomized trial aimed at bridging the gap between primary and emergency care for asthma, a chart review study of the significance of antimicrobial resistance in pneumococcal infections, a prospective cohort study of viral respiratory pathogens in COPD exacerbations, and a prospective cohort study of predictors of severe bronchiolitis. An ongoing study (MARC-30) will examine the etiology of bronchiolitis in 15 North American hospitals.

Health Policy

At the core of our health services research are the National ED Inventories and the National ED Safety Study (NEDSS). The National ED Inventories (NEDI) are ongoing surveys that contain data on all EDs in a specific nation (or city) including facility location and annual visit volume. For the US, EMNet staff created an inventory of all EDs using data from two different national sources. Data were enhanced through data collection at hundreds of hospitals to complete missing fields and reconcile discrepancies. NEDSS examined if ED staff perceptions of systemic factors affecting patient safety are associated with the occurrence of adverse events and lower quality care. These databases, combined with US Census data and other resources, will allow the EMNet Coordinating Center to perform innovative health services research.

Public Health Projects

In addition to airway/allergy emergencies and health policy, EMNet also works on other public health topics. For example, the Emergency Department 24-hour Research Network (ED24) is a US research network focusing on public health issues that affect the delivery and quality of emergency care, as well as the primary care needs of medically disadvantaged populations. Brief multicenter studies (e.g., 24-hours) are the core activity of this program.

The first ED24 study was a multicenter trial to examine if a simple outreach would increase CHIP enrollment among uninsured children presenting to the emergency department. Subsequent studies have examined ED crowding, the effectiveness of a simple ED intervention to prevent falls among the elderly, screening for mood disorders, diabetes screening, food security, health literacy, and interest among ED patients and visitors in public health issues.

EMNet also is involved in several other public-health related studies, including analyses of federal datasets. For example, the EMNet Coordinating Center has combined all available years of the National Hospital Ambulatory Medical Care Survey (NHAMCS) emergency department data (1992-2005). NHAMCS is a national probability sample survey of visits to the EDs of nonfederal, short-stay hospitals in the US. The EMNet Coordinating Center continues to analyze this combined dataset in collaboration with a growing number of EMNet investigators.

EMNet Leadership & Support

In 1996, the principal investigator of EMNet, Dr. Carlos Camargo, formed the first EMNet Steering Committee to help guide this large collaboration. The current leadership of EMNet, as well as a listing of all US sites (n=166) may be found elsewhere on the EMNet website (click here). Although EMNet research is usually done in US hospitals, sites outside the US (n=32) have participated in several studies. Given the very large number of sites, and frequent relocations of ED staff, it’s impractical to provide individual names and locations of the hundreds and hundreds of site investigators that have participated in past studies. However, EMNet Coordinating Center staff, based at the Massachusetts General Hospital (Boston, MA), would be happy to answer individual queries (emnet@partners.org).

Financial support for EMNet has come from many sources, including federal grants (K, R01, R03, R13, T32, U01), industry grants, and a variety of other sources. For example, EMNet was honored in 2000 by receipt of the Emergency Medicine Foundation “Center of Excellence Award.”

In 2006, the NIH-funded Inventory and Evaluation of Clinical Research Networks (IECRN) selected EMNet as a "Best Practice" Network. IECRN is charged with identifying best practices in research networks (www.clinicalresearchnetworks.org). Such networks successfully achieve specified outcomes, including increased efficiency, promotion of interactivity within the network and across networks, and broadening of their research scope. EMNet was selected as a leader in collaborative research because of our expanding research scope, training programs, and extensive publication record. Of >260 networks, 29 were chosen for the Best Practices Study. EMNet is the only emergency medicine research network selected for this honor.

Expectations of Investigators

Initial expectations – from the early MARC studies – have evolved as the network diversifies and grows. At this point, we are doing different types of studies at different sites based on each site's data collection experience, patient population, and the interest of investigators at that site. Accordingly, expectations of investigators will differ greatly across studies.

In consultation with the EMNet Steering Committee, the network is eager to work with investigators who would like to use the network to perform studies of their own design! Funding is, of course, the major obstacle to the realization of most multicenter projects …. However, the Steering Committee will continue to do all that it can to help EMNet investigators to secure national abstract presentations, scientific publications, and grant awards.

To date, more than 200 EMNet manuscripts have been published in a variety of journals (Acad Emerg Med, Am J Emerg Med, Am J Respir Crit Care Med, Ann Emerg Med, Arch Intern Med, Chest, Eur Respir J, J Allergy Clin Immunol, J Pediatrics, and Respir Care). Click here for a list of EMNet publications. To date, EMNet publications have included over 375 investigators at 115 sites. By encouraging all of the EMNet investigators to participate in the dissemination of the results, and to assume leadership roles, we have made EMNet a collaboration that will renew itself many times over in the years ahead.

Joining the Network

For further information about EMNet activities, please contact:

Carlos A. Camargo, MD, DrPH
Director, EMNet Coordinating Center
Department of Emergency Medicine
Massachusetts General Hospital
326 Cambridge Street, Suite 410
Boston, MA 02114
Tel (617) 726-5276 / Fax (617) 724-4050
email: emnet@partners.org

If you are interested in joining EMNet, please complete an investigator form. If you prefer, please send us an e-mail (emnet@partners.org), and we will help you get started. We hope you'll join us!


©2010 EMNet Last Updated: 06/16/08 as