title: Survival and re-operation rates after neurosurgical procedures in Scotland: implications for targeted surveillance of sub-clinical variant Creutzfeldt-Jakob disease.
abstract: OBJECTIVE
  To assess the feasibility of post-mortem surveillance for subclinical variant Creutzfeldt-Jakob disease (vCJD) at least 5 years after neurosurgical procedures.
  
  
  METHODS
  Using Scottish record linkage, we estimated 5-year survival and re-operation rates after 4 neurosurgical procedures performed during 1993-2001 and identified as high or medium risk for transmitting vCJD: [B] drainage of extra- or subdural haematoma, [E] primary or revisional decompression operations and [H] creation of other ventricular shunts were classified as high risk; [C] operations on cerebral aneurysm (clipping) were classified as medium risk.
  
  
  RESULTS
  Fatality rate at 1 year depended strongly on procedure, weakly or not at all on sex and era, and increased with age. Procedure rates differed by sex. The rate of subsequent neurosurgical operations was highest for procedure [H] (sole: 21%; multiple: 28%).
  
  
  CONCLUSIONS
  Each year, the UK has a new cohort of some 5,000 5-year survivors after a high- or medium-risk neurosurgical procedure, whose subsequent annual mortality is at least 3%. Even if half the surviving 5-year survivors of neurosurgery since 1996 gave consent-in-life for vCJD-informative testing at post-mortem, there would be too few relevant post-mortems in 2008-2010 (around 1,600) for 'nil detections' to exclude a 1 in 1,000 subclinical vCJD rate. Autopsy surveillance beyond 2010, or among 5-year survivors of non-neurosurgical at-risk operations, would be needed.
authors.affiliation: MRC Biostatistics Unit, Cambridge, UK. sheila.bird@mrc-bsu.cam.ac.uk
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Bird
authors.forename: Elizabeth L C
authors.initials: EL
authors.lastname: Merrall
authors.forename: Hester J T
authors.initials: HJ
authors.lastname: Ward
authors.forename: Robert G
authors.initials: RG
authors.lastname: Will
mesh_terms: D000328:Adult; D001344:Autopsy / Q000706:statistics & numerical data; D007562:Creutzfeldt-Jakob Syndrome / Q000401:mortality / Q000601:surgery / Q000635:transmission; D004866:Equipment Contamination; D005260:Female; D006801:Humans; D008297:Male; D019635:Neurosurgical Procedures / Q000009:adverse effects* / Q000401:mortality / Q000706:statistics & numerical data*; D016012:Poisson Distribution; D011159:Population Surveillance; D012086:Reoperation / Q000009:adverse effects* / Q000401:mortality / Q000706:statistics & numerical data*; D012307:Risk Factors; D012606:Scotland / Q000453:epidemiology; D013525:Surgical Instruments; D015996:Survival Rate