When Change Healthcare, a subsidiary of UnitedHealth Group, got hit by a cyberattack this winter, a big chunk of the nation’s doctors, pharmacists, hospitals, and therapists stopped getting paid. The hack also limited health providers’ ability to share medical records and other information critical to patient care. The cyberattack revealed an often overlooked part of how health care is paid for in the United States and raised concerns for antitrust advocates about how large UnitedHealth has grown. Host Dan Weissmann speaks with reporters Brittany Trang of Stat News and Maureen Tkacik of The Am…