title: An optimization framework for measuring spatial access over healthcare networks.
abstract: BACKGROUND
  Measurement of healthcare spatial access over a network involves accounting for demand, supply, and network structure. Popular approaches are based on floating catchment areas; however the methods can overestimate demand over the network and fail to capture cascading effects across the system.
  
  
  METHODS
  Optimization is presented as a framework to measure spatial access. Questions related to when and why optimization should be used are addressed. The accuracy of the optimization models compared to the two-step floating catchment area method and its variations is analytically demonstrated, and a case study of specialty care for Cystic Fibrosis over the continental United States is used to compare these approaches.
  
  
  RESULTS
  The optimization models capture a patient's experience rather than their opportunities and avoid overestimating patient demand. They can also capture system effects due to change based on congestion. Furthermore, the optimization models provide more elements of access than traditional catchment methods.
  
  
  CONCLUSIONS
  Optimization models can incorporate user choice and other variations, and they can be useful towards targeting interventions to improve access. They can be easily adapted to measure access for different types of patients, over different provider types, or with capacity constraints in the network. Moreover, optimization models allow differences in access in rural and urban areas.
authors.affiliation: H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, USA. zli66@gatech.edu.
authors.forename: Zihao
authors.initials: Z
authors.lastname: Li
authors.affiliation: H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, USA. nserban@isye.gatech.edu.
authors.forename: Nicoleta
authors.initials: N
authors.lastname: Serban
authors.affiliation: H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, USA. jswann@isye.gatech.edu.|School of Public Policy by courtesy, Georgia Institute of Technology, Atlanta, USA. jswann@isye.gatech.edu.
authors.forename: Julie L
authors.initials: JL
authors.lastname: Swann
mesh_terms: D002391:Catchment Area, Health; D006297:Health Services Accessibility; D006801:Humans; D008962:Models, Theoretical; D012424:Rural Population; D062211:Spatio-Temporal Analysis; D014481:United States