title: Geographical variation in certification rates of blindness and sight impairment in England, 2008-2009.
abstract: OBJECTIVE
  To examine and interpret the variation in the incidence of blindness and sight impairment in England by PCT, as reported by the Certificate of Vision Impairment (CVI).
  
  
  METHODS
  Analysis of national certification data.
  
  
  METHODS
  All Primary Care Trusts, England.
  
  
  METHODS
  23 773 CVI certifications issued from 2008 to 2009.
  
  
  METHODS
  Crude and Age standardised rates of CVI data for blindness and sight loss by PCT.
  
  
  METHODS
  The crude and age standardised CVI rates per 100 000 were calculated with Spearman's rank correlation used to assess whether there was any evidence of association between CVI rates with Index of Multiple Deprivation (IMD) and the Programme Spend for Vision.
  
  
  RESULTS
  There was high-level variation, almost 11-fold (coefficient of variation 38%) in standardised CVI blindness and sight impairment annual certification rates across PCTs. The mean rate was 43.7 and the SD 16.7. We found little evidence of an association between the rate of blindness and sight impairment with either the IMD or Programme Spend on Vision.
  
  
  CONCLUSIONS
  The wide geographical variation we found raises questions about the quality of the data and whether there is genuine unmet need for prevention of sight loss. It is a concern for public health practitioners who will be interpreting these data locally and nationally as the CVI data will form the basis of the public health indicator 'preventable sight loss'. Poor-quality data and inadequate interpretation will only create confusion if not addressed adequately from the outset. There is an urgent need to address the shortcomings of the current data collection system and to educate all public health practitioners.
authors.affiliation: Moorfields Eye Hospital, London,  UK.
authors.forename: Aeesha N J
authors.initials: AN
authors.lastname: Malik
authors.forename: Catey
authors.initials: C
authors.lastname: Bunce
authors.forename: Richard
authors.initials: R
authors.lastname: Wormald
authors.forename: Mehrunisha
authors.initials: M
authors.lastname: Suleman
authors.forename: Irene
authors.initials: I
authors.lastname: Stratton
authors.forename: J A Muir
authors.initials: JA
authors.lastname: Gray