Creating a unique patient identifier for every U.S. resident could cost as much as $11 billion, but would likely return even more in benefits to the nation’s health care system, according to new RAND Corp. study. Such a system would help reduce medical errors, simplify the use of electronic medical records, increase overall efficiency and help protect patient privacy, the authors conclude. “Establishing a system of unique patient identification numbers would help the nation to enjoy the full benefits of electronic medical records and improve the quality of medical care,” said lead author Richard Hillestad, a senior principal researcher at RAND.