Implementation of a Pilot ACO Payment Model and the Use of Discretionary and Non-Discretionary Cardiovascular Care

Study Questions:

What is the impact of a pilot accountable care organization (ACO) payment model on spending around cardiovascular care?


ACOs are increasingly being considered as a strategy for reducing healthcare spending, while at the same time ensuring high-quality care. Despite growing interest in ACOs, there is little empirical evidence on their real-world implications for specialty-based care. Accordingly, these authors evaluated whether ACO implementation within the highly-visible Physician Group Practice Demonstration (PGPD) impacted on the utilization of services related to coronary and carotid disease within the Medicare population.


The intervention group was composed of fee-for-service Medicare patients (n = 819,779) from 10 groups participating in pilot PGPD. Matched controls were patients (n = 934,621) from nonparticipating groups in the same regions. Utilization of cardiovascular care before (2002-2004) and after implementation (2005-2009) was compared with difference-in-difference methods, after stratifying care in discretionary and nondiscretionary services based on the acute presentation of acute myocardial infarction or stroke. Overall, their results found that there were no differences between PGPD practices and non-PGPD practices for both discretionary and nondiscretionary imaging studies and procedures.


The authors concluded that: “Implementation of a pilot ACO did not limit the utilization of discretionary or nondiscretionary cardiovascular care in 10 large health systems.”


Full disclosure: I am a co-author on this paper so I obviously like it. ACOs are a highly-visible payment reform tool being used by policymakers to help reduce healthcare spending while ensuring quality. They are supported by the Affordable Care Act and are meant to be transformative. Despite great interest in ACOs, there are limitations to them that need to be considered. This paper meant to ask and answer a seemingly simple question: How do specialists and specialty care fit into this equation of ACOs? Unfortunately, the bottom line appears to be ‘very little,’ which is concerning if these payment reform tools are to gain even more momentum. In the discussion, the authors outline their rationale for why these null results may have occurred, focusing on the lack of involvement of specialists in the design of ACOs. This is a major problem, since specialty care (like cardiovascular services) drives a lot of the costs of modern healthcare. Better systems are needed to engage specialists with primary care providers in ACOs if their promised savings are to be truly realized.

Keywords: Specialization, Myocardial Infarction, Stroke, Fee-for-Service Plans, Health Expenditures, Accountable Care Organizations, Medicare, Patient Protection and Affordable Care Act, Primary Health Care

< Back to Listings