title: Analysis of patient flows for orthopedic procedures using small area analysis in Switzerland.
abstract: BACKGROUND
  In general cantons regulate and control the Swiss health service system; patient flows within and between cantons are thereby partially disregarded. This paper develops an alternative spatial model, based upon the construction of orthopedic hospital service areas (HSAOs), and introduces indices for the analysis of patient streams in order to identify areas, irrespective of canton, with diverse characteristics, importance, needs, or demands.
  
  
  METHODS
  HSAOs were constructed using orthopedic discharge data. Patient streams between the HSAOs were analysed by calculating three indices: the localization index (% local residents discharged locally), the netindex (the ratio of discharges of nonlocal incoming residents to outgoing local residents), and the market share index (% of local resident discharges of all discharges in local hospitals).
  
  
  RESULTS
  The 85 orthopedic HSAOs show a median localization index of 60.8%, a market share index of 75.1%, and 30% of HSAOs have a positive netindex. Insurance class of bed, admission type, and patient age are partially but significantly associated with those indicators. A trend to more centrally provided health services can be observed not only in large urban HSAOs such as Geneva, Bern, Basel, and Zurich, but also in HSAOs in mountain sport areas such as Sion, Davos, or St.Moritz. Furthermore, elderly and emergency patients are more frequently treated locally than younger people or those having elective procedures.
  
  
  CONCLUSIONS
  The division of Switzerland into HSAOs provides an alternative spatial model for analysing and describing patient streams for health service utilization. Because this small area model allows more in-depth analysis of patient streams both within and between cantons, it may improve support and planning of resource allocation of in-patient care in the Swiss healthcare system.
authors.affiliation: Institute for Evaluative Research in Orthopedic Surgery, MEM centre, University of Bern, Stauffacherstrasse, Bern, Switzerland. klazien.matter@memcenter.unibe.ch
authors.forename: Klazien
authors.initials: K
authors.lastname: Matter-Walstra
authors.forename: Marcel
authors.initials: M
authors.lastname: Widmer
authors.forename: André
authors.initials: A
authors.lastname: Busato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001265:Athletic Injuries / Q000453:epidemiology / Q000601:surgery; D002391:Catchment Area, Health / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D040362:Geographic Information Systems; D005843:Geography; D006297:Health Services Accessibility / Q000706:statistics & numerical data; D006752:Hospital Planning; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009051:Mountaineering / Q000293:injuries; D020380:Needs Assessment; D019637:Orthopedic Procedures / Q000706:statistics & numerical data*; D017062:Small-Area Analysis; D013557:Switzerland / Q000453:epidemiology