title: Physician practice participation in accountable care organizations: the emergence of the unicorn.
abstract: OBJECTIVE
  To provide the first nationally based information on physician practice involvement in ACOs.
  
  
  METHODS
  Primary data from the third National Survey of Physician Organizations (January 2012-May 2013).
  
  
  METHODS
  We conducted a 40-minute phone survey in a sample of physician practices. A nationally representative sample of practices was surveyed in order to provide estimates of organizational characteristics, care management processes, ACO participation, and related variables for four major chronic illnesses.
  
  
  METHODS
  We evaluated the associations between ACO participation, organizational characteristics, and a 25-point index of patient-centered medical home processes.
  
  
  RESULTS
  We found that 23.7 percent of physician practices (n = 280) reported joining an ACO; 15.7 percent (n = 186) were planning to become involved within the next 12 months and 60.6 percent (n = 717) reported no involvement and no plans to become involved. Larger practices, those receiving patients from an IPA and/or PHO, those that were physician-owned versus hospital/health system-owned, those located in New England, and those with greater patient-centered medical home (PCMH) care management processes were more likely to have joined an ACO.
  
  
  CONCLUSIONS
  Physician practices that are currently participating in ACOs appear to be relatively large, or to be members of an IPA or PHO, are less likely to be hospital-owned and are more likely to use more care management processes than nonparticipating practices.
authors.affiliation: School of Public Health, University of California, Berkeley, 50 University Hall, MC 7360, Berkeley, CA 94720.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Shortell
authors.forename: Sean R
authors.initials: SR
authors.lastname: McClellan
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Ramsay
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Casalino
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Ryan
authors.forename: Kennon R
authors.initials: KR
authors.lastname: Copeland
mesh_terms: D060866:Accountable Care Organizations / Q000639:trends*; D001249:Asthma / Q000628:therapy; D003327:Coronary Disease / Q000628:therapy; D003695:Delivery of Health Care / Q000639:trends*; D003863:Depression / Q000628:therapy; D003920:Diabetes Mellitus / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058991:Patient Protection and Affordable Care Act; D018802:Patient-Centered Care / Q000639:trends*; D010819:Physician's Role; D010818:Practice Patterns, Physicians' / Q000458:organization & administration* / Q000639:trends*; D014481:United States
keywords: Accountable care organizations; Affordable Care Act; care management; physician practices