Five major health care organizations are banding together in a nationwide call for action to address racial and ethnic disparities in health care. The effort comes as the nation faces the dual challenge of moving forward with the health system reform law and an increasingly diverse population. Racial and ethnic minorities represent a third of the U.S. population and are projected to make up the majority of the population by 2042. "Disparities are an urgent issue," said Bruce Siegel, MD, MPH, president and CEO of the National Assn. of Public Hospitals and Health Systems. "We are at a tipping point…