In this way, Dowling says, "we can achieve enormous efficiencies, although it will take us two years to get this all done."
All regulatory and board approvals have been obtained.
For now, physician staffs will remain mostly separate. Most of NS-LIJ's network of 8,000 doctors and Lenox Hill's 600 physicians will still practice at their respective hospitals.
NS-LIJ is the ninth-largest employer in New York City with 38,000 employees, including 9,500 nurses, and the largest on Long Island. It cares for more than 325,000 patients a year.
A spokesperson for Lenox Hill could not be reached for an interview, but Gladys George, president and chief executive officer of the hospital, said in a statement that "We are confident that our patients will benefit from North Shore-LIJ's nationally recognized quality initiatives, depth of clinical services, and new medical school being developed with Hofstra University."
North Shore LIJ says it expects to find out in June whether the new school meets preliminary accreditation standards, and if it does, expects to open in the summer of 2011.
According to a joint statement, Lenox Hill is described as ranking "among the nation's top hospitals in heart and heart surgery, digestive disorders, and neurology and neurosurgery" in U.S. News and World Report, and is recognized nationally for its orthopedic surgery, sports medicine, and maternal/child health lines of service.
It also has pioneered in off-pump heart bypass surgery, robotic cardiac surgery, and interventional treatment of carotid stenosis and aortic disease.
The announcement comes only two weeks after the closure of another New York landmark, 160-year-old St. Vincent's Hospital.