title: Changes in Quality of Health Care Delivery after Vertical Integration.
abstract: OBJECTIVE
  To fill an empirical gap in the literature by examining changes in quality of care measures occurring when multispecialty clinic systems were acquired by hospital-owned, vertically integrated health care delivery systems in the Twin Cities area.
  
  
  METHODS
  Administrative data for health plan enrollees attributed to treatment and control clinic systems, merged with U.S. Census data.
  
  
  METHODS
  We compared changes in quality measures for health plan enrollees in the acquired clinics to enrollees in nine control groups using a differences-in-differences model. Our dataset spans 2 years prior to and 4 years after the acquisitions. We estimated probit models with errors clustered within enrollees.
  
  
  METHODS
  Data were assembled by the health plan's informatics team.
  
  
  RESULTS
  Vertical integration is associated with increased rates of colorectal and cervical cancer screening and more appropriate emergency department use. The probability of ambulatory care-sensitive admissions increased when the acquisition caused disruption in admitting patterns.
  
  
  CONCLUSIONS
  Moving a clinic system into a vertically integrated delivery system resulted in limited increases in quality of care indicators. Caution is warranted when the acquisition causes disruption in referral patterns.
authors.affiliation: Medica Research Institute, Minneapolis, MN.
authors.forename: Caroline S
authors.initials: CS
authors.lastname: Carlin
authors.affiliation: Division of Health Policy and Management, University of Minnesota, Minneapolis, MN.
authors.forename: Bryan
authors.initials: B
authors.lastname: Dowd
authors.affiliation: Division of Health Policy and Management, University of Minnesota, Minneapolis, MN.
authors.forename: Roger
authors.initials: R
authors.lastname: Feldman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019033:Delivery of Health Care, Integrated / Q000458:organization & administration* / Q000706:statistics & numerical data*; D055088:Early Detection of Cancer / Q000706:statistics & numerical data; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data; D011787:Quality of Health Care / Q000706:statistics & numerical data*; D012959:Socioeconomic Factors; D014481:United States; D055815:Young Adult
keywords: Vertical integration; provider consolidation; quality of care