Spreading a medical home redesign: effects on emergency department use and hospital admissions.

PURPOSE: The patient-centered medical home (PCMH) is being rapidly deployed in many settings to strengthen US primary care, improve quality, and control costs; however, evidence supporting this transformation is still lacking. We describe the Group Health experience in attempting to replicate the effects on health care use seen in a PCMH prototype clinic via a systemwide spread using Lean as the change strategy.
METHODS: We used an interrupted time series analysis with a patient-month unit of analysis over a 4-year period that included baseline, implementation, and stabilization periods for 412,943 patients. To account for secular trends across these periods, we compared changes in use of face-to-face primary care visits, emergency department visits, and inpatient admissions with those of a nonequivalent comparison group of patients served by community network practices.
RESULTS: After accounting for secular trends among network patients, patients empaneled to the PCMH clinics had 5.1% and 6.7% declines in primary care office visits in early and later stabilization years, respectively, after the implementation year. This trend was accompanied by a 123% increase in the use of secure electronic message threads and a 20% increase in telephone encounters. Declines were also seen in emergency department visits at 1 and 2 years (13.7% and 18.5%) compared with what would be expected based on secular trends in network practices. No statistically significant changes were found for hospital admissions.
CONCLUSIONS: The Group Health experience shows it is possible to reduce emergency department use with PCMH transformation across a diverse set of clinics using a clear change strategy (Lean) and sufficient resources and supports.