UCLA Health System tries to ensure that doctors spend more time with patients and work more closely with parents to coordinate care. The program has cut emergency room visits by slightly more than half. The effort is part of a much broader ambition by UCLA Health System to reduce its costs by 30 percent, or hundreds of millions of dollars, over the next five years, according to Dr. David T. Feinberg, the system's president. Hospitals, doctors and health insurers say there is a strong effort under way to slash the rate of growth in the nation's $2.7 trillion healthcare bill by roughly half to keep it more in line with overall inflation.