Overlap between Medicare's Voluntary Bundled Payment and Accountable Care Organization Programs

Population turnover and leakage in commercial ACOs

OBJECTIVES

Commercial accountable care organization (ACO) contracts attempt to mitigate spending growth, but past evaluations have been limited to continuously enrolled ACO members in health maintenance organization (HMO) plans, excluding many members. The objective of this study was to examine the magnitude of turnover and leakage within a commercial ACO.

STUDY DESIGN

A historical cohort study using detailed information from multiple commercial ACO contracts within a large health care system between 2015 and 2019.

METHODS

Individuals insured through 1 of the 3 largest commercial ACO contracts during the study period, 2015-2019, were included. We examined patterns of entry and exit and the characteristics that predicted remaining in the ACO compared with leaving the ACO. We also examined predictors of the amount of care delivered in the ACO compared with outside the ACO.

RESULTS

Among the 453,573 commercially insured individuals in the ACO, approximately half left the ACO within the initial 24 months after entry. Approximately one-third of spending was for care occurring outside the ACO. Patients who remained in the ACO differed from those who left earlier, including being older, having a non-HMO plan, having lower predicted spending at entry, and having more medical spending for care performed within the ACO during the initial quarter of membership.

CONCLUSIONS

Both turnover and leakage hamper the ability of ACOs to manage spending. Modifications that address potentially intrinsic vs avoidable sources of population turnover and increase patient incentives for care within vs outside of ACOs could help address medical spending growth within commercial ACO programs.

Overlap Between Medicare's Comprehensive Care for Joint Replacement Program and Accountable Care Organizations

BACKGROUND

Overlap between Medicare's Comprehensive Care for Joint Replacement (CJR) model and accountable care organizations (ACOs) may result in positive or negative synergies. In this study, we describe the overlap between the programs at the beneficiary and hospital levels.

METHODS

We conducted a retrospective study of patient and hospital characteristics using data from 2016 Medicare claims, the US Census Bureau, the American Hospital Association annual survey, Hospital Compare, and the Centers for Medicare & Medicaid Services Improving Medicare Post-Acute Care Transformation file. On the beneficiary level, we conducted 2 comparisons: (1) among patients who received joint replacement at CJR hospitals, ACO patients (overlap) vs not (CJR-only) and 2) among patients who received joint replacement elsewhere, ACO patients (ACO-only) vs not (neither). On the hospital level, we compared hospitals in the top quartile of overlap rate (high overlap) vs those in the bottom 3 (low overlap).

RESULTS

We studied 14,519 overlap, 38,972 CJR-only, 26,872 ACO-only, and 68,945 neither beneficiaries. Compared with CJR-only patients, the overlap group was less likely to be older than 85, of black race, of low socioeconomic status, and burdened with clinical complications. Similar results were observed when the ACO-only group was compared with the neither group. Compared with low overlap hospitals, high overlap ones were more likely to be of nonprofit and less likely to be of safety net.

CONCLUSION

CJR-ACO overlap is associated with differences in beneficiary and hospital characteristics, which raises key issues for providers and policymakers.