title: Changes in Emergency Department Use Among Young Adults After the Patient Protection and Affordable Care Act's Dependent Coverage Provision.
abstract: OBJECTIVE
  Since September 2010, the Patient Protection and Affordable Care Act has allowed young adults to remain as dependents on their parents' private health plans until age 26 years. This insurance expansion could improve the efficiency of medical care delivery by reducing unnecessary emergency department (ED) use. We evaluated the effect of this provision on ED use among young adults.
  
  
  METHODS
  We used a nationally representative ED visit database of more than 17 million visits from 2007 to 2011. Our analysis compared young adults aged 19 to 25 years (the age group targeted by the law) with slightly older adults aged 27 to 29 years (control group), before and after the implementation of the law.
  
  
  RESULTS
  The quarterly ED-visit rate decreased by 1.6 per 1,000 population (95% confidence interval 1.2 to 2.1) among targeted young adults after the implementation of the provision, relative to a comparison group. The decrease was concentrated among women, weekday visits, nonurgent conditions, and conditions that can be treated in other settings. We found no effect among weekend visits or visits due to injuries or urgent conditions. The provision also changed the health insurance composition of ED visits; the fraction of privately insured young adults increased, whereas the fraction of those insured through Medicaid and those uninsured decreased.
  
  
  CONCLUSIONS
  The Patient Protection and Affordable Care Act dependent coverage expansion was associated with a statistically significant yet modest decrease in ED use, concentrated in the types of ED visits that were likely to be responsive to changes to insurance status. In response to the law, young adults appeared to have altered their visit pattern to reflect a more efficient use of medical care.
authors.affiliation: Department of Economics, Indiana University-Purdue University Indianapolis, Indianapolis, IN.
authors.forename: Yaa
authors.initials: Y
authors.lastname: Akosa Antwi
authors.affiliation: School of Public and Environmental Affairs, Indiana University, Bloomington, IN; Center for Financing, Access and Cost Trends, Agency for Healthcare Research and Quality, Rockville, MD. Electronic address: asako.moriya@ahrq.hhs.gov.
authors.forename: Asako S
authors.initials: AS
authors.lastname: Moriya
authors.affiliation: School of Public and Environmental Affairs, Indiana University, Bloomington, IN; NBER, Boston, MA.
authors.forename: Kosali
authors.initials: K
authors.lastname: Simon
authors.affiliation: Department of Health Policy and Management, Harvard School of Public Health, Boston, MA; Department of Medicine, Brigham & Women's Hospital, Boston, MA.
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Sommers
mesh_terms: D000328:Adult; D000367:Age Factors; D004636:Emergency Service, Hospital / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D019458:Insurance Coverage / Q000331:legislation & jurisprudence* / Q000706:statistics & numerical data; D008297:Male; D058991:Patient Protection and Affordable Care Act / Q000706:statistics & numerical data*; D055815:Young Adult