Implementation of a Pilot Accountable Care Organization Payment Model and the Use of Discretionary and Nondiscretionary Cardiovascular Care

Abstract

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.

Consistency of Hemoglobin A1c Testing and Cardiovascular Outcomes in Medicare Patients With Diabetes

“…Death was assessed using the Denominator file. Myocardial infarction was defined using International Classification of Diseases, Ninth Revision (ICD‐9) diagnosis codes as in previous reports 23. Stroke was defined using ICD‐9 codes, as published previously.…”

“…Stroke was defined using ICD‐9 codes, as published previously. We used a 1‐year look back to exclude patients in whom any of the cardiovascular events occurred in the past year 23, 24. We recorded the occurrence of a major lower‐extremity amputation at the patient level, using current procedural terminology codes indicative of above‐ or below‐knee amputation.…”

Legal and Policy Interventions to Improve Patient Safety

“…71 Another recent analysis revealed that ACO implementation did not affect spending on discretionary or nondiscretionary imaging and procedures for cardiovascular conditions. 72 Outcomes such as performance on heart failure admissions and blood pressure control will continue to feature prominently in such evaluations; almost half of CMS's quality measures for ACOs relate to cardiovascular care. 73 More data and time are needed to properly determine whether this model will be successful in improving safety, including whether the shared savings incentives could have unintended consequences such as underuse that threaten patient safety.…”

Opportunities and Accountable Care Organizations

“…By studying nondiscretionary carotid and coronary imaging and procedure codes, researchers found no difference in utilization of discretionary or nondiscretionary cardiovascular care among Accountable Care Organization patients and matched controls [12]. Opportunities in payment reform can address imaging utilization and hospital readmissions through physician leadership, which can positively affect oncology care [13].…”