title: Spreading a medical home redesign: effects on emergency department use and hospital admissions.
abstract: OBJECTIVE
  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.
authors.affiliation: Group Health Physicians, Seattle, Washington 98101, USA. reid.rj@ghc.org
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Reid
authors.forename: Eric A
authors.initials: EA
authors.lastname: Johnson
authors.forename: Clarissa
authors.initials: C
authors.lastname: Hsu
authors.forename: Kelly
authors.initials: K
authors.lastname: Ehrlich
authors.forename: Katie
authors.initials: K
authors.lastname: Coleman
authors.forename: Claire
authors.initials: C
authors.lastname: Trescott
authors.forename: Michael
authors.initials: M
authors.lastname: Erikson
authors.forename: Tyler R
authors.initials: TR
authors.lastname: Ross
authors.forename: David T
authors.initials: DT
authors.lastname: Liss
authors.forename: DeAnn
authors.initials: D
authors.lastname: Cromp
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fishman
mesh_terms: D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D018802:Patient-Centered Care / Q000458:organization & administration*; D011320:Primary Health Care / Q000458:organization & administration*; D014481:United States
keywords: Lean; change management; delivery of health care; family practice; medical home; practice-based research; primary health care