title: Towards a reliable and accurate ethnicity database at district and national levels: progress in Canterbury.
abstract: OBJECTIVE
  To analyse the extent of ethnicity and related recording in Canterbury primary health organisations (PHOs), to examine variation between general practices and PHOs in ethnicity recording, and to compare the findings with census figures with particular reference to Māori.
  
  
  METHODS
  Data for July 2009 from the five Canterbury PHOs were analysed. Totals and rates for different categories of ethnicity were calculated including ethnicity 'not stated'. Differences in rates between general practices for ethnicity 'not stated' were calculated. The results were compared with census figures for different ethnicities.
  
  
  RESULTS
  A total population of 476,042 was analysed of whom 6.2% were Māori and 2.1% Pacific people. 'No ethnicity' was recorded for only 3.4% of the population. This figure varied from 0.4 to 4.5% between PHOs but was much wider between practices. Comparison with census figures showed that 95.4% of the Canterbury district population were enroled. Only 76.4% of Māori were classified as enroled as compared with the census estimates.
  
  
  CONCLUSIONS
  Canterbury PHOs/general practices, along with national PHOs, have reduced ethnicity 'not stated' to almost negligible levels. The difference between the PHO and census figures for Māori is probably due to the different systems used by Statistics New Zealand for the census and for health classifications. Nationally there are now some 102,000 less in the PHO data as compared with census estimates. However the PHO general practice records should now be used to provide an accurate and up-to-date district and national database for analysis and funding. In doing so it ensures that calculated morbidity and other rates use an identical denominator and numerator.
authors.affiliation: Aotearoa Health, Christchurch, New Zealand. lm@cyberxpress.co.nz
authors.forename: Laurence
authors.initials: L
authors.lastname: Malcolm
mesh_terms: D019352:Censuses; D005006:Ethnicity / Q000706:statistics & numerical data*; D006801:Humans; D009520:New Zealand / Q000208:ethnology; D015203:Reproducibility of Results; D012189:Retrospective Studies; D011795:Surveys and Questionnaires