title: Data quality of surgery for carotid artery stenosis. Are the national vascular registries reliable?
abstract: OBJECTIVE
  To study completeness of reporting carotid endarterectomies, including peri-operative stroke and mortality rate, in a national vascular registry, NorKar, and a national administrative registry, The Norwegian Patient Register (NPR).
  
  
  METHODS
  Comparative registry-based national study.
  
  
  METHODS
  Member hospitals of NorKar, including 89% of carotid endarterectomies in Norway, were compared with relevant data in NPR for the years 2000-2002.
  
  
  METHODS
  We compared procedure-codes, diagnosis-codes, in-hospital death and the occurrence of peri-operative stroke after treatment for carotid artery stenosis in the two registries to evaluate completeness.
  
  
  RESULTS
  Compared with the NPR numbers, 16% of carotid endarterectomies were missing in the reports from member hospitals of NorKar. Further, during this three-year period, there was an under-reporting of seven strokes and two deaths. The discrepancy was most pronounced in 2001.
  
  
  CONCLUSIONS
  There is an under-reporting of patients operated on for carotid artery stenosis in NorKar according to NPR numbers as well as an under-reporting of early deaths and strokes. There is a need for better quality data in the NorKar Registry. Registry quality would be likely to improve if patient identifiable data were available in both registries.
authors.affiliation: Department of Surgery, St Olavs Hospital, University Hospital of Trondheim, N-7006 Trondheim, Norway.
authors.forename: T
authors.initials: T
authors.lastname: Dahl
authors.forename: K
authors.initials: K
authors.lastname: Rudjord
authors.forename: M
authors.initials: M
authors.lastname: Altreuther
authors.forename: H O
authors.initials: HO
authors.lastname: Myhre
mesh_terms: D000800:Angioplasty, Balloon / Q000009:adverse effects; D016893:Carotid Stenosis / Q000401:mortality / Q000601:surgery*; D016894:Endarterectomy, Carotid / Q000009:adverse effects* / Q000401:mortality* / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006801:Humans; D009664:Norway / Q000453:epidemiology; D011785:Quality Assurance, Health Care; D012042:Registries / Q000592:standards*; D015607:Stents / Q000009:adverse effects; D020521:Stroke / Q000453:epidemiology