Wider use of hospital observation units could save the U.S. healthcare system billions of dollars a year, a new study indicates. Only about one-third of U.S. hospitals have observation units. Researchers at Brigham and Women's Hospital, in Boston, analyzed national survey data and published research to determine the average cost saving per observation unit and the number of hospitals that would benefit from having such a unit. They concluded that the average amount saved per patient could be $1,572 per visit when using an observation unit instead of inpatient admission. A hospital would save $4.6 million a year by avoiding 3,600 inpatient admissions.