title: Late-in-life surgery associated with Creutzfeldt-Jakob disease: a methodological outline for evidence-based guidance.
abstract: BACKGROUND
  There is increasing epidemiological evidence of etiological links between general surgery and sporadic Creutzfeldt-Jakob disease (sCJD) with long incubation periods. The purpose of this study was to identify specific surgical procedures potentially associated with sCJD to be targeted for preventive presurgical-intervention guidance.
  
  
  RESULTS
  We propose a three-step clinical guidance outline where surgical procedures associated with sCJD clinical onset - potentially more contaminant - are taken into account. Data on hospital discharges and surgical procedures were obtained from Danish and Swedish national in-patient hospital registries for 167 sCJD cases, onset 1987-2003, and for 835 matched and 2,224 unmatched population controls. Surgery was allocated to different life-time periods as previously reported, and frequencies were compared using logistic regression analysis. In the year preceding clinical onset, persons with sCJD underwent a statistically significant higher number of minor surgical interventions (OR (95% CI): 17.50 (3.64-84.24)), transluminal endoscopies (OR: 2.73 (1.01-7.37)) and gastrointestinal operations (OR: 3.51 (1.21-10.19)) compared to matched controls. Surgical discharges clustered towards clinical onset. These differences increased during the clinical period, with statistically significant higher frequencies for both endoscopies and minor surgery (OR: 13.91 (5.87-32.95), and for main surgical procedures (OR: 2.10 (1.00-4.39)), particularly gastrointestinal surgery (OR: 6.00 (1.83-19.66)), and surgery contacting skeletal muscle. Comparisons with unmatched controls yielded similar results for neurosurgery in the clinical period (OR: 19.40 (2.22-168.34)).
  
  
  CONCLUSIONS
  These results suggest that some types of surgical procedures are associated with sCJD, after clinical onset or particularly just before onset. Selective planning of such surgery to minimize instrument/device contamination or quarantining might be feasible. Conditional to progress in sCJD etiological research, results are relevant for guidance development.
authors.affiliation: Department of Applied Epidemiology, National Center for Epidemiology, Carlos III Institute of Health, C/ Sinesio Delgado 6, Madrid 28029, Spain. jpedro@isciii.es.
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