HCR Update from Mark Sanna: Aetna, Humana, Kaiser Permanente and UnitedHealthcare have agreed to provide their claims data to a new nonprofit research initiative called the Health Care Cost Institute. The institute will have more than 5 billion medical claim records representing more than $1 trillion of health care spending in private plans and Medicare Advantage plans. The researchers’ are salivating because the patterns of medical care for people with private insurance — two thirds of the covered population — mostly remain a mystery, even as health care costs threaten to bankrupt the nation.