title: Effect of insurance expansion on utilization of inpatient surgery.
abstract: OBJECTIVE
  Enhanced access to preventive and primary care services is a primary focus of the Affordable Care Act, but the potential effect of this law on surgical care is not well defined.
  
  
  OBJECTIVE
  To estimate the differential effect of insurance expansion on utilization of discretionary vs nondiscretionary inpatient surgery with Massachusetts health care reform as a natural experimental condition.
  
  
  METHODS
  We used the state inpatient databases from Massachusetts and 2 control states (New Jersey and New York) to identify nonelderly adult patients (aged 19-64 years) who underwent discretionary vs nondiscretionary surgical procedures from January 1, 2003, through December 31, 2010. We defined discretionary surgery as elective, preference-sensitive procedures (eg, joint replacement and back surgery) and nondiscretionary surgery as imperative and potentially life-saving procedures (eg, cancer surgery and hip fracture repair).
  
  
  METHODS
  All surgical procedures in the study and control populations.
  
  
  METHODS
  Using July 1, 2007, as the transition point between the prereform and postreform periods, we performed a difference-in-differences analysis to estimate the effect of insurance expansion on rates of discretionary and nondiscretionary surgical procedures in the entire study population and for subgroups defined by race, income, and insurance status. We then extrapolated our results from Massachusetts to the entire US population.
  
  
  RESULTS
  We identified a total of 836 311 surgical procedures during the study period. Insurance expansion was associated with a 9.3% increase in the use of discretionary surgery in Massachusetts (P = .02). Conversely, the rate of nondiscretionary surgery decreased by 4.5% (P = .009). We found similar effects for discretionary surgery in all subgroups, with the greatest increase observed for nonwhite participants (19.9% [P < .001]). Based on the findings in Massachusetts, we estimated that full implementation of national insurance expansion would yield an additional 465 934 discretionary surgical procedures by 2017.
  
  
  CONCLUSIONS
  Insurance expansion in Massachusetts was associated with increased rates of discretionary surgery and a concurrent decrease in rates of nondiscretionary surgery. If similar changes are seen nationally under the Affordable Care Act, the value of insurance expansion for surgical care may depend on the relative balance between increased expenditures and potential health benefits of greater access to elective inpatient procedures.
authors.affiliation: Department of Urology, Medical School, University of Michigan, Ann Arbor2Center for Healthcare Outcomes & Policy, University of Michigan, Ann Arbor3Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor.
authors.forename: Chandy
authors.initials: C
authors.lastname: Ellimoottil
authors.affiliation: Robert Wood Johnson Foundation Scholar in Health Policy Research, University of Michigan, Ann Arbor.
authors.forename: Sarah
authors.initials: S
authors.lastname: Miller
authors.affiliation: Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor5Division of General Medicine, Medical School, University of Michigan, Ann Arbor6Department of Health Management and Policy, School of Public Health, University of Michigan, An.
authors.forename: John Z
authors.initials: JZ
authors.lastname: Ayanian
authors.affiliation: Department of Urology, Medical School, University of Michigan, Ann Arbor2Center for Healthcare Outcomes & Policy, University of Michigan, Ann Arbor3Institute for Healthcare Policy & Innovation, University of Michigan, Ann Arbor.
authors.forename: David C
authors.initials: DC
authors.lastname: Miller
mesh_terms: D000328:Adult; D017558:Elective Surgical Procedures / Q000706:statistics & numerical data; D005260:Female; D018166:Health Care Reform / Q000458:organization & administration*; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D019458:Insurance Coverage / Q000458:organization & administration*; D008297:Male; D008404:Massachusetts; D008875:Middle Aged; D009515:New Jersey; D009518:New York; D058991:Patient Protection and Affordable Care Act; D012959:Socioeconomic Factors; D013514:Surgical Procedures, Operative / Q000706:statistics & numerical data*; D055815:Young Adult