The Comprehensive Primary Care Plus Model and Health Care Spending, Service Use, and Quality

Importance

Implemented in 18 regions, Comprehensive Primary Care Plus (CPC+) was the largest U.S. primary care delivery model ever tested. Understanding its association with health outcomes is critical in designing future transformation models.

Objective

To test whether CPC+ was associated with lower health care spending and utilization and improved quality of care.

Design, Setting, and Participants

Difference-in-differences regression models compared changes in outcomes between the year before CPC+ and five intervention years for Medicare fee-for-service beneficiaries attributed to CPC+ and comparison practices. Participants included 1,373 Track 1 (1,549,585 beneficiaries) and 1,151 Track 2 (5,347,499 beneficiaries) primary care practices that applied to start CPC+ in 2017 and met minimum care delivery and other eligibility requirements. Comparison groups included 5,243 Track 1 (5,347,499 beneficiaries) and 3,783 Track 2 (4,507,499 beneficiaries) practices, matched, and weighted to have similar beneficiary-, practice-, and market-level characteristics as CPC+ practices.

Interventions

Two-track design involving enhanced (higher for Track 2) and alternative payments (Track 2 only), care delivery requirements (greater for Track 2), data feedback, learning, and health information technology support.

Main Outcomes and Measures

The prespecified primary outcome was annualized Medicare Part A and B expenditures per beneficiary per month (PBPM). Secondary outcomes included expenditure categories, utilization (e.g., hospitalizations), and claims-based quality-of-care process and outcome measures (e.g., recommended tests for patients with diabetes and unplanned readmissions).

Results

Among the CPC+ patients, 5% were Black, 3% were Hispanic, 87% were White, and 5% were of other races (including Asian/Other Pacific Islander and American Indian); 85% of CPC+ patients were older than 65 years and 58% were female. CPC+ was associated with no discernible changes in the total expenditures (Track 1: $1.1 PBPM, [90% CI, –$4.3 to $6.6], P = 0.74; Track 2: $1.3 [90% CI, -$5 to $7.7], P = 0.73), and with increases in expenditures including enhanced payments (Track 1: $13 [90% CI, $7 to $18], P < 0.001; Track 2: $24 [90% CI, $18 to $31, P < 0.001). Among secondary outcomes, CPC+ was associated with decreases in emergency department visits starting in year 1, and in acute hospitalizations and acute inpatient expenditures in later years. Associations were more favorable for practices also participating in the Medicare Shared Savings Program and independent practices. CPC+ was not associated with meaningful changes in claims-based quality-of-care measures.

Conclusions and Relevance

Although the timing of associations of CPC+ with reduced utilization and acute inpatient expenditures was consistent with the theory of change and early focus on episodic care management of CPC+, CPC+ was not associated with a reduction in total expenditures over five years. Positive interaction between CPC+ and the Shared Savings Program suggests transformation models might be more successful when provider cost-reduction incentives are aligned across specialties. Further adaptations and testing of primary care transformation models, as well as consideration of the larger context in which they operate, are needed.