The Multicenter Airway Research Collaboration (MARC) was created by 12 emergency physicians in May 1996 to determine the best management of acute asthma in the emergency department. The principal investigator of MARC, Dr. Carlos Camargo, formed the MARC Steering Committee to help guide this collaboration. The MARC Coordinating Center is based at the Massachusetts General Hospital (Boston, MA). Financial support for MARC has come from a variety of sources, including government, foundations, and industry. The NHLBI study used MARC databases.