title: Implications of the Patient Protection and Affordable Care Act on Insurance Coverage and Rehabilitation Use Among Young Adult Trauma Patients.
abstract: Trauma is the leading cause of death and disability among young adults, who are also among the most likely to be uninsured. Efforts to increase insurance coverage, including passage of the Patient Protection and Affordable Care Act (ACA), were intended to improve access to care and promote improvements in outcomes. However, despite reported gains in coverage, the ACA's success in promoting use of high-quality care and enacting changes in clinical end points remains unclear.
  
  
  
  To assess for observed changes in insurance coverage and rehabilitation use among young adult trauma patients associated with the ACA, including the Dependent Coverage Provision (DCP) and Medicaid expansion/open enrollment, and to consider possible insurance and rehabilitation differences between DCP-eligible vs -ineligible patients and among stratified demographic and community subgroups.
  
  
  
  A longitudinal assessment of DCP implementation and Medicaid expansion/open enrollment using risk-adjusted before-and-after, difference-in-difference, and interrupted time-series analyses was conducted. Eleven years (January 1, 2005, to September 31, 2015) of Maryland Health Services Cost Review Commission data, representing complete patient records from all payers within the state, were used to identify all hospitalized young adult (aged 18-34 years) trauma patients in Maryland during the study period.
  
  
  
  Of the 69 507 hospitalized patients included, 50 548 (72.7%) were male, and the mean (SD) age was 25 (5) years. Before implementation of the DCP, 1 of 4 patients was uninsured. After ACA implementation, the number fell to less than 1 of 10, with similar patterns emerging in emergency department and outpatient settings. The change was primarily driven by Medicaid expansion/open enrollment, which corresponded to a 20.1 percentage-point increase in Medicaid (95% CI, 18.9-21.3) and an 18.2 percentage-point decrease in uninsured (95% CI, -19.3 to -17.2). No changes were detected among privately insured patients. Rehabilitation use increased by 5.4 percentage points (95% CI, 4.5-6.2)-a 60% relative increase from a baseline of 9%. Mortality (-0.5; 95% CI, -0.9 to -0.1) and failure-to-rescue rates (-4.5; 95% CI, -7.4 to -1.6) also significantly declined. Stratified changes point to significant differences in the percentage of uninsured patients and rehabilitation access across the board, mitigating or even eradicating disparities in certain cases.
  
  
  
  For patients who are injured, young, and uninsured, Medicaid expansion/open enrollment in Maryland changed insurance coverage and altered patient outcomes in ways that the DCP alone was never intended to do. Implementation of Medicaid expansion/open enrollment transformed the landscape of trauma coverage, directly affecting the health of one of the country's most vulnerable at-risk groups.
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts2Johns Hopkins Surgery Center for Outcomes Research, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland3now a graduate student, Yale School of Medicine, New Haven, Connecticut.
authors.forename: Cheryl K
authors.initials: CK
authors.lastname: Zogg
authors.affiliation: Department of Economics, Boston University, Boston, Massachusetts.
authors.forename: Fernando
authors.initials: F
authors.lastname: Payró Chew
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: John W
authors.initials: JW
authors.lastname: Scott
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Lindsey L
authors.initials: LL
authors.lastname: Wolf
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Tsai
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Peter
authors.initials: P
authors.lastname: Najjar
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Olubode A
authors.initials: OA
authors.lastname: Olufajo
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts2Johns Hopkins Surgery Center for Outcomes Research, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Schneider
authors.affiliation: Johns Hopkins Surgery Center for Outcomes Research, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland4Department of Economics, Boston University, Boston, Massachusetts5Division of Acute Care Surgery, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland6Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland7Department of Emergency Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland8Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Haut
authors.affiliation: Center for Surgery and Public Health, Harvard Medical School, Harvard T. H. Chan School of Public Health, Boston, Massachusetts, Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts.
authors.forename: Adil H
authors.initials: AH
authors.lastname: Haider
authors.affiliation: Johns Hopkins Surgery Center for Outcomes Research, Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Canner
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D019458:Insurance Coverage / Q000706:statistics & numerical data*; D007348:Insurance, Health / Q000706:statistics & numerical data*; D065186:Interrupted Time Series Analysis; D008137:Longitudinal Studies; D008297:Male; D008396:Maryland; D008484:Medicaid / Q000706:statistics & numerical data*; D058991:Patient Protection and Affordable Care Act; D014481:United States; D014947:Wounds and Injuries / Q000534:rehabilitation*; D055815:Young Adult