title: The use of control charts in monitoring postcataract surgery endophthalmitis.
abstract: OBJECTIVE
  To apply the control chart method to retrospectively analyse the variation in postcataract surgery endophthalmitis.
  
  
  METHODS
  The endophthalmitis data between 01/07/97 and 30/06/07 (10 years) at the Royal Gwent Hospital were analysed using the control chart method. Certain criteria related to the control chart were employed to detect unusual variations and early outbreaks of endophthalmitis.
  
  
  RESULTS
  A total of 21 032 cases of cataract were performed in that period, with a mean annual incidence of 0.16%. The control chart could provide a reliable method to detect an early outbreak of endophthalmitis before it was suspected and acted on. The chart provided visual information of the altering trends of endophthalmitis cases and allows unusual variations to be detected early.
  
  
  CONCLUSIONS
  The control chart is potentially a sensitive method to detect anomaly in the cases of postcataract surgery endophthalmitis. Its control limits are dynamic and factor in recent performance to detect any unusual variation.
authors.affiliation: Eye Department, Royal Gwent Hospital, Newport, UK. pjtchiam@yahoo.com
authors.forename: P J T
authors.initials: PJ
authors.lastname: Chiam
authors.forename: A
authors.initials: A
authors.lastname: Feyi-Waboso
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002387:Cataract Extraction; D019468:Disease Management; D004196:Disease Outbreaks / Q000517:prevention & control* / Q000706:statistics & numerical data; D009877:Endophthalmitis / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D014792:Visual Acuity