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Limited Impact of Medicare ACOs on Mental Illness Care and Management

August 23, 2016

Recent data show a limited impact on the care and management of patients with mental illness enrolled in Medicare Accountable Care Organizations (ACOs).

In a study that looked at changes in mental health spending, utilization, and quality measures associated with ACO contracts in the Medicare Shared Savings Program and the Pioneer model for beneficiaries with mental illness, investigators from Harvard Medical School found no changes in any of these measures when compared to local non-ACO providers.

To assess the impact of Medicare ACO contracts on the care and management of patients with mental illness, investigators used Medicare claims and enrollment data from a random 20% sample of fee-for-service adult beneficiaries between 2008 and 2013 who had at least one acute mental health hospitalization or at least two outpatient mental health diagnoses at least 7 days apart and compared the data to local non-ACO providers.  Mental health diagnoses were grouped into categories: major depressive disorder, other depression diagnosis, and anxiety; and schizophrenia, bipolar disorder, other paranoid states, and nonorganic psychoses.

Evaluation of the impact of Medicare ACO contracts on mental health spending and utilization included an assessment of the annual Medicare spending on mental health care by setting (ie, outpatient, in patient, or emergency department) and utilization of mental health services (ie, inpatient admissions, emergency room visits, partial hospitalizations medication management or office visits, and outpatient psychotherapy.

The study also assessed three claims-based quality measures for Pioneer and Medicare Shared Savings Program ACOs. These three quality measures included 1) beneficiaries who were admitted during any given year for mental illness, 2) the proportions of beneficiaries admitted who were readmitted within 30 days of discharge and had received an outpatient mental health follow-up within 7 days of discharge, and 3) beneficiaries diagnosed with depressive disorder.

The only impact found was a lower spending on mental health admissions in the first year of the contract for Pioneer contracts. However, this impact was attenuated in the second year of the contract. No other changes in the three quality measures assessed were associated with ACO contracts.

“These results suggest that ACOs have not yet focused on mental illness or have been largely unsuccessful in early efforts to improve their management of it,” conclude the investigators. –Mary Beth Nierengarten


Busch AB, Huskamp HA, McWilliams JM. Early efforts by medicare accountable care organizations have limited effect on mental illness care and management [published online July 2016]. Health Aff. 2016;35(7):1247-1256.

Syrop J. Medicare ACOs have only limited effect on care of mental illness. August 20, 2016.


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