title: The effect of emergency department copayments for Medicaid beneficiaries following the Deficit Reduction Act of 2005.
abstract: OBJECTIVE
  High unemployment during the 2007-2009 Great Recession and eligibility expansions have increased the size and cost of Medicaid. To provide states with flexibility in administering the program while containing costs, the Deficit Reduction Act of 2005 (DRA) gave states the authority to impose cost-sharing strategies, including emergency department (ED) copayments for nonurgent visits. To our knowledge, there has been no previous longitudinal analysis of the effect of the DRA on health care utilization outcomes for Medicaid beneficiaries.
  
  
  OBJECTIVE
  To evaluate the effect of the DRA, which allowed states to enforce ED copayments for nonurgent visits, on ED utilization among Medicaid beneficiaries and to compare the effect among beneficiaries living in states that did and did not adopt ED copayments.
  
  
  METHODS
  A difference-in-difference quasi-experimental approach was used to compare trends in ED use among Medicaid beneficiaries from January 2001 to December 2010. Eight states with ED copayments for nonurgent ED visits (copayment states) were compared with 10 states with zero ED copayments (control states). The study cohort was the population of individuals 19 to 64 years old enrolled in Medicaid for a full calendar year as collected by the Medical Expenditure Panel Survey, a nationally representative survey of noninstitutionalized US civilians. The cohort consisted of 3122 adult Medicaid recipients in copayment states and 7433 adult Medicaid recipients in control states.
  
  
  METHODS
  The main exposure was the copayment enforcement authority of the DRA. The study controlled for sex, age, race, marital status, income relative to the federal poverty level, educational level, and self-reported health status.
  
  
  METHODS
  The primary outcome of this study was the change in the rate of ED utilization following the DRA. Additional outcomes included changes in the rate of outpatient medical provider visits and inpatient length of stay. Visits were not coded according to urgency, which prevented us from examining only nonurgent ED use.
  
  
  RESULTS
  Estimates from a zero-inflated Poisson regression model detected no statistically significant change in annual ED admissions per Medicaid enrollee (change, 0.05; 95% CI, -0.05 to 0.16) in copayment states compared with control states following the DRA. There was also no change in the rate of outpatient medical provider visits (change, 0.02; 95% CI, -0.31 to 0.35) or in annual inpatient days (change, 0.13; 95% CI, -0.31 to 0.57) per Medicaid enrollee.
  
  
  CONCLUSIONS
  Granting states permission to collect copayments for nonurgent visits under the DRA did not significantly change ED or outpatient medical provider use among Medicaid beneficiaries.
authors.affiliation: Division of General Internal Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland2currently with the White House Social and Behavioral Sciences Team, Washington, DC.
authors.forename: Mona
authors.initials: M
authors.lastname: Siddiqui
authors.affiliation: Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Eric T
authors.initials: ET
authors.lastname: Roberts
authors.affiliation: Division of General Internal Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland3Department of Health Policy and Management, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Craig E
authors.initials: CE
authors.lastname: Pollack
mesh_terms: D000328:Adult; D017047:Cost Sharing / Q000331:legislation & jurisprudence*; D004522:Educational Status; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007182:Income; D008137:Longitudinal Studies; D008297:Male; D017533:Marital Status; D008484:Medicaid / Q000191:economics*; D008875:Middle Aged; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D044469:Racial Groups; D014481:United States