title: A Difference-in-Difference Analysis of Changes in Quality, Utilization and Cost Following the Colorado Multi-Payer Patient-Centered Medical Home Pilot.
abstract: BACKGROUND
  Research on the effects of patient-centered medical homes on quality and cost of care is mixed, so further study is needed to understand how and in what contexts they are effective.
  
  
  OBJECTIVE
  We aimed to evaluate effects of a multi-payer pilot promoting patient-centered medical home implementation in 15 small and medium-sized primary care groups in Colorado.
  
  
  METHODS
  We conducted difference-in-difference analyses, comparing changes in utilization, costs, and quality between patients attributed to pilot and non-pilot practices.
  
  
  METHODS
  Approximately 98,000 patients attributed to 15 pilot and 66 comparison practices 2 years before and 3 years after the pilot launch.
  
  
  METHODS
  Healthcare Effectiveness Data and Information Set (HEDIS) derived measures of diabetes care, cancer screening, utilization, and costs to payers.
  
  
  RESULTS
  At the end of two years, we found a statistically significant reduction in emergency department use by 1.4 visits per 1000 member months, or approximately 7.9 % (p = 0.02). At the end of three years, pilot practices sustained this difference with 1.6 fewer emergency department visits per 1000 member months, or a 9.3 % reduction from baseline (p = 0.01). Emergency department costs were lower in the pilot practices after two (13.9 % reduction, p < 0.001) and three years (11.8 % reduction, p = 0.001). After three years, compared to control practices, primary care visits in the pilot practices decreased significantly (1.5 % reduction, p = 0.02). The pilot was associated with increased cervical cancer screening after two (12.5 % increase, p < 0.001) and three years (9.0 % increase, p < 0.001), but lower rates of HbA1c testing in patients with diabetes (0.7 % reduction at three years, p = 0.03) and colon cancer screening (21.1 % and 18.1 % at two and three years, respectively, p < 0.001). For patients with two or more comorbidities, similar patterns of association were found, except that there was also a reduction in ambulatory care sensitive inpatient admissions (10.3 %; p = 0.05).
  
  
  CONCLUSIONS
  Our findings suggest that a multi-payer, patient-centered medical home initiative that provides financial and technical support to participating practices can produce sustained reductions in utilization with mixed results on process measures of quality.
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA. meredith_rosenthal@harvard.edu.|Department of Health Policy and Management, Harvard School of Public Health, 677 Huntington Avenue, Boston, MA, 02115, USA. meredith_rosenthal@harvard.edu.
authors.forename: Meredith B
authors.initials: MB
authors.lastname: Rosenthal
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Shehnaz
authors.initials: S
authors.lastname: Alidina
authors.affiliation: RAND Corporation, Santa Monica, CA, USA.|Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Mark W
authors.initials: MW
authors.lastname: Friedberg
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.|Massachusetts General Hospital, Boston, MA, USA.
authors.forename: Sara J
authors.initials: SJ
authors.lastname: Singer
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Diana
authors.initials: D
authors.lastname: Eastman
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Zhonghe
authors.initials: Z
authors.lastname: Li
authors.affiliation: Harvard T.H. Chan School of Public Health, Boston, MA, USA.|RAND Corporation, Santa Monica, CA, USA.|Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Schneider
mesh_terms: D000328:Adult; D003120:Colorado / Q000453:epidemiology; D004636:Emergency Service, Hospital / Q000191:economics* / Q000592:standards; D005260:Female; D017048:Health Care Costs / Q000592:standards; D006801:Humans; D008297:Male; D008875:Middle Aged; D018802:Patient-Centered Care / Q000191:economics* / Q000592:standards; D010865:Pilot Projects; D011787:Quality of Health Care / Q000191:economics* / Q000592:standards
keywords: health care costs; patient-centered care; primary care redesign; quality improvement