title: Construction and use of mapping techniques to describe the geographical distribution of medication dispensing for the secondary prevention of atherosclerotic CVD in New Zealand: VIEW-2.
abstract: BACKGROUND
  The Health Quality and Safety Commission (HQSC) is developing Atlases of Healthcare Variation in New Zealand. We were invited to create and map the sociogeographic distribution of medication dispensing patterns among people with atherosclerotic cardiovascular disease (CVD).
  
  
  METHODS
  We developed two interactive online atlas 'templates' demonstrating geographical variations in CVD medication dispensing using InstantAtlas. Each template provides stratified results in tabular, graphical and map format. In the 'Standard' template proportions were mapped according to standard deviations from the mean, while the 'Advanced' template used a 'heat-map' classification to show DHB-level variations. Furthermore, we added commentaries describing the variations present and provided questions of potential interest for users.
  
  
  RESULTS
  The Standard template was best suited for DHB-level variations relative to a specific age, gender, or ethnic group but less effective for showing comparisons between two groups (e.g. Maori and Pacific). By contrast, the fixed legend and 'radar plot' in the Advanced template highlighted variations in medication dispensing rates geographically and sociodemographically more effectively.
  
  
  CONCLUSIONS
  Geographical mapping of unwarranted variations in effective care requires careful consideration. Our experience from developing this CVD atlas is documented here for developers of other components of the Atlas of Healthcare Variation in New Zealand.
authors.affiliation: Section of Epidemiology and Biostatistics, University of Auckland, Auckland, PB 92019, Auckland Mail Centre 1142, New Zealand. d.exeter@auckland.ac.nz.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Exeter
authors.forename: Jinfeng
authors.initials: J
authors.lastname: Zhao
authors.forename: Grant
authors.initials: G
authors.lastname: Hanham
authors.forename: Corina
authors.initials: C
authors.lastname: Grey
authors.forename: Sue
authors.initials: S
authors.lastname: Wells
authors.forename: Andrew
authors.initials: A
authors.lastname: Kerr
mesh_terms: D000328:Adult; D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001271:Atlases as Topic; D003324:Coronary Artery Disease / Q000453:epidemiology / Q000517:prevention & control*; D016208:Databases, Factual; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004359:Drug Therapy, Combination / Q000706:statistics & numerical data; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D055502:Secondary Prevention; D012984:Software
chemical_list: D000925:Anticoagulants; D000959:Antihypertensive Agents; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors