Implementation of a Pilot ACO Payment Model and the Use of Discretionary and Non-Discretionary Cardiovascular Care
Background—Accountable care organizations (ACOs) seek to reduce growth in healthcare spending while ensuring high-quality care. We hypothesized that ACO implementation would selectively limit utilization of discretionary cardiovascular care (defined as care occurring in the absence of indications such as myocardial infarction or stroke), while maintaining high-quality care such as non-discretionary cardiovascular imaging and procedures.
Methods and Results—The intervention group was composed of fee-for-service Medicare patients (n=819,779) from 10 groups participating in a Medicare pilot ACO, the Physician Group Practice Demonstration (PGPD). Matched controls were patients (n=934,621) from non-participating groups in the same regions. We compared utilization of cardiovascular care before (2002-2004) and after (2005-2009) PGPD implementation, studying both discretionary and non-discretionary carotid and coronary imaging and procedures. Our main outcome measure was the difference in the proportion of patients treated with imaging and procedures, among patients of PGPD practices compared to patients in control practices, before and after PGPD implementation (difference-in-difference). For discretionary imaging, the difference-in-difference between PGPD practices and controls was not statistically significant for discretionary carotid imaging (0.17%; 95% CI -0.51% to 0.85%, p=0.595) or discretionary coronary imaging (-0.19%; 95% CI -0.73% to 0.35%, p=0.468). Similarly, the difference-in-difference was also minimal for discretionary carotid revascularization (0.003%; 95% CI -0.008% to 0.002%, p=0.705) and coronary revascularization (-0.02%, 95% CI -0.11% to 0.07%, p=0.06). The difference-in-difference associated with PGPD implementation was also essentially zero for non-discretionary cardiovascular imaging or procedures.
Conclusions—Implementation of a pilot ACO did not limit the utilization of discretionary or non-discretionary cardiovascular care in ten large health systems.
- health policy and outcomes research
- stroke care
- myocardial infarction
- outcomes research
- health economics
- Received May 30, 2014.
- Revision received August 22, 2014.
- Accepted September 11, 2014.