title: A framework to evaluate the effects of small area variations in healthcare infrastructure on diagnostics and patient outcomes of rare diseases based on administrative data.
abstract: BACKGROUND
  Small area variations in healthcare infrastructure may result in differences in early detection and outcomes for patients with rare diseases.
  
  
  METHODS
  It is our aim to provide a framework for evaluating small area variations in healthcare infrastructure on the diagnostics and health outcomes of rare diseases. We focus on administrative data as it allows (a) for relatively large sample sizes even though the prevalence of rare diseases is very low, and (b) makes it possible to link information on healthcare infrastructure to morbidity, mortality, and utilization.
  
  
  RESULTS
  For identifying patients with a rare disease in a database, a combination of different classification systems has to be used due to usually multiple diseases sharing one ICD code. Outcomes should be chosen that are (a) appropriate for the disease, (b) identifiable and reliably coded in the administrative database, and (c) observable during the limited time period of the follow-up. Risk adjustment using summary scores of disease-specific or comprehensive risk adjustment instruments might be preferable over empirical weights because of the lower number of variables needed.
  
  
  CONCLUSIONS
  The proposed framework will help to identify differences in time to diagnosis and treatment outcomes across areas in the context of rare diseases.
authors.affiliation: Hamburg Center for Health Economics, University of Hamburg, Esplanade 36, 20354 Hamburg, Germany. tom.stargardt@wiso.uni-hamburg.de
authors.forename: Tom
authors.initials: T
authors.lastname: Stargardt
authors.forename: Jonas
authors.initials: J
authors.lastname: Schreyögg
mesh_terms: D003695:Delivery of Health Care / Q000458:organization & administration / Q000592:standards / Q000706:statistics & numerical data*; D006291:Health Policy; D006801:Humans; D038801:International Classification of Diseases; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000706:statistics & numerical data; D015397:Program Evaluation / Q000379:methods; D035583:Rare Diseases / Q000175:diagnosis* / Q000628:therapy; D020379:Risk Adjustment / Q000379:methods; D017062:Small-Area Analysis