The impact of patient-centered medical homes on safety net clinics

To evaluate the impact of moving to a patient-centered medical home (PCMH) model in safety net clinics in a managed Medicaid plan.

Quasi-experimental, difference-in-differences design.

The study examined whether the PCMH model reduced emergency department (ED) use and whether the growth in the seniors and people with disabilities (SPDs) population crowds out lower-cost populations. The study compared 7 PCMH safety net clinics (22,870 members) in late 2011 in the greater Los Angeles area with 110 general safety net clinics (143,530 members) between January 2011 and December 2013. During the time from 2011 to 2012, California began transitioning SPDs from fee-for-service Medicaid into managed care systems under a federal waiver.

Among clinics with less than 10% SPD membership, a PCMH model was associated with more office visits and less ED use. In particular, PCMH clinics-relative to non-PCMH clinics-reduced ED visits by an average of 70 visits per 1000 members per year (PTMPY) and reduced avoidable ED visits by 20 visits PTMPY. Neither the change in office visits nor ED visits was evident in clinics with SPD membership greater than 10%.

Adopting a PCMH model in safety net practices can effectively reduce ED use and increase the use of office visits among Medicaid patients. However, the beneficial effects of the PCMH model can be muted by a sudden influx of high-need users.