ACOs Lean More on Physician Assistants, Non-Physician Providers

Accountable care organizations (ACOs) are relying more on physician assistants, nurse practitioners, and other non-physician providers to deliver high-quality, low-cost care to assigned patients, according to a recent CMS study.

Published in the most recent edition of Health Affairs, researchers from CMS and the Dartmouth Institute for Health Policy and Clinical Medicine found that ACOs increased the average number of non-physician practitioners in the organization from 47 to 245 clinicians between 2013 and 2018, with physician assistants seeing the most growth.

The prevalence of physician assistants averaged less than 1 percent of ACO clinicians during the first four years of the study to more than 13 percent by the last two years, the study showed. Nurse practitioners saw similar growth, with average prevalence increasing from 17.6 percent to 25.0 percent during the period.

In contrast, the average number of participating primary care physicians increased from an average of 141 to 251 clinicians, while the average number of medical specialists rose from 76 to 157 clinicians.

Overall, the average prevalence of non-physician practitioners exceeded that of medical specialists starting in 2016 (25.5 percent versus 21.5 percent).

Leveraging more non-physician practitioners could lower the intensity of use for assigned beneficiaries, making shared savings more achievable while increasing the chances that patients with ongoing care needs are attributed to the ACO, researchers stated.

In 2016, CMS started to allow non-physician practitioners (i.e., nurse practitioners, physician assistants, and clinical nurse specialists) to be part of the first stage of patient assignment in which patients are assigned to ACO based on who billed for the plurality of qualifying primary care services. Patients are assigned first through qualifying services billed by an ACO’s primary care physicians, then non-physician practitioners and medical specialists.

The new policy paved the way for ACOs to add more physician assistants, nurse practitioners, and other non-physician providers to their ACO rosters. However, quality of care may also have played a role, researchers stated.

“Although nonphysician practitioners may work with primary care physicians or medical specialists, ACOs may have added more of them because their quality of care has been shown to be comparable to the quality of care of primary care physicians while their billing rates are lower,” researchers wrote in the study.

Critics of expanding scope of practice laws for non-physician practitioners argue that giving physician assistants, nurse practitioners, and other similar providers a larger role in care delivery could water down quality of care. However, research has demonstrated that leveraging non-physician practitioners can improve access to care, drive practice efficiency, and lower costs for complex patients.

The ACO model may represent a major growth opportunity for both the nurse practitioner and physician assistant workforces, the CMS study indicated.

Non-physician practitioner workforces are already experiencing significant growth. Nurse practitioner employment is slated to increase by 84 percent by 2025, according to a New England Journal of Medicine report. Physician assistants are also expected to face similar growth.

Some researchers have linked the growth in these workforces with the worsening physician shortage, especially among primary care physicians. However, the implementation of value-based care may also be driving greater use of non-physician practitioners, researchers found.

“Our results suggest that ACOs’ clinician composition may shape the future health care workforce as value-based care models play a more common role in the delivery system,” they wrote.

Previous research has shown that ACOs have engaged in new staffing models to provide additional support to high-risk patients. Leveraging non-physician practitioners, including medical assistants, was a major component of the restructuring.

Nurse practitioners and physician assistants are playing a growing role in delivering annual wellness visits, chronic care management visits, and transitional care management visits, which are accessed by more Medicare patients in ACOs than in fee-for-service, CMS researchers stated.

These providers could also address the physician shortage as well as physician burnout by supporting team-based care in which patients rely on physicians less often.

“As payments from value-based care models gradually displace fee-for-service Medicare payments, health care organizations such as ACOs will have greater flexibility to try new ways of delivering care,” they concluded. “Nonphysician practitioners may bolster an ACO’s capacity to deliver care while providing physicians with additional support to meet the needs of patients. In turn, ACOs may provide a platform for the growth of nonphysician practitioners in the greater health care system.”