Accountable care organizations in the USA: types, developments and challenges.

A historically fragmented U.S. health care system, where care has been delivered by multiple providers with little or no coordination, has led to increasing issues with access, cost, and quality. The Affordable Care Act included provisions to use Medicare, the U.S. near universal public coverage program for older adults, to broadly implement Accountable Care Organization (ACO) models with a triple aim of improving the experience of care, the health of populations, and reducing per capita costs. Private payers in the U.S. are also embracing ACO models. Various European countries are experimenting with similar reforms, particularly those in which coordinated (or integrated) care from a network of providers is reimbursed with bundled payments and/or shared savings. The challenges for these reforms remain formidable and include: (1) overcoming incentives for ACOs to engage in rationing and denial of care and taking on too much financial risk, (2) collecting meaningful data that capture quality and enable rewarding quality improvement and not just volume reduction, (3) creating incentives for ACOs that do not accept much risk to engage in prevention and health promotion, and (4) creating effective governance and IT structures that are patient-centered and integrate care.