A broad collection of health care stakeholders -- including health care provider and consumer advocacy groups, insurers, researchers, union leaders and think tanks opposite one another on the political spectrum -- are calling on Congress to enact a set of site-neutral provisions lobbyists say aren’t currently expected to clear the Senate . The open letter comes as staunch opponents of site-neutral policies ramp up their advertising campaigns amid the ongoing scramble to move appropriations legislation. A burgeoning food fight between...