Accountable care organizations, designed to reduce overhead and improve health outcomes by coordinating care, may not be achieving either goal when it comes to patients with complex needs, according to several new studies.

ACOs’ self-reported management and coordination activities were not associated with improved outcomes or lower spending for elderly patients with multiple diagnoses, according to a Dartmouth Institute for Health Policy & Clinical Practice study published in JAMA Network Open last week.

Researchers examined records related to 1.4 million Medicare beneficiaries who had frailty or multiple chronic conditions and were assigned to an ACO. They compared outcomes among groups whose ACOs used varying care management tactics, including follow-up calls to general practitioners; patient navigators; and in-home visits.

Among potential strategies for transitioning patients to home or post–acute care, more than 90% of ACOs in the study’s top care-management tier said they 1) provided medication reconciliation, 2) transmitted discharge summaries to other practitioners or 3) placed follow-up phone calls within 72 hours of discharge.

But there was no significant difference between the ACOs providing the most coordination and those providing the least.

“When focusing on whether care management and coordination efforts by ACOs were associated with outcomes in older adults with complex needs, we did not find any statistically significant associations between care management and coordination and measures of care quality, utilization, spending, or interactions with the healthcare system,” the team reported.

Overall, Medicare beneficiaries who remain in the same accountable care organization over a four-year period have been found to have 10% lower healthcare costs.

But a June report from the Medicare Payment Advisory Commission showed that costs skyrocketed for ACO beneficiaries who had a catastrophic health event.

The Dartmouth researchers said providers should reassess whether approaches used in more general settings work for patients with complex needs.

A second study published last week found the use of specialists helped some accountable care organizations reduce spending, as well as emergency department visits, hospital discharges, skilled nursing facility discharges, and magnetic resonance imaging orders.

Researchers determined that ACOs that used specialists to conduct 40%-45% of office visits spent significantly less than ACOs with lower or higher specialist involvement.

“Sustained reductions in spending for Medicare may not be achievable without sufficient involvement in the care processes by specialists,” reported a team from the University of Massachusetts-Amherst.

That study, also published in JAMA Network Open, found specialists “complement the intrinsic primary care approach in ACOs.” But finding some types of specialists is especially challenging in rural areas, or even nationwide as in the case of geriatricians.