title: Risk of venous thromboembolism in children after general surgery.
abstract: OBJECTIVE
  The purpose of the study was to determine absolute and relative rates of venous thromboembolism (VTE) following general surgical procedures in children compared to the general population.
  
  
  METHODS
  We analyzed data from all patients under the age of 18years in the Clinical Practice Research Datalink, linked to Hospital Episode Statistics from England (2001-2011) undergoing a general surgical procedure and population controls. Crude rates of VTE and adjusted hazard ratios were calculated using Cox regression.
  
  
  RESULTS
  We identified 15,637 children who had a surgical procedure with 161,594 controls. Six children undergoing surgery had a VTE diagnosed in the year after compared to five children in the population cohort. The overall rate of VTE following surgery was 0.4 per 1000 person years (pyrs) (95% confidence interval [CI] 0.15-0.88) compared to 0.04 per 1000 pyrs (95% CI 0.02-0.09) in the population cohort. This represented a 9 fold increase in risk compared to the population cohort (adjusted hazard ratio [HR] 8.80; 95% CI 2.59-29.94).
  
  
  CONCLUSIONS
  Children are at increased risk for VTE following general surgical procedures compared to the general population however the absolute risk is small and given this the benefits of thromboprophylaxis need to be balanced against the risk of complications following its use.
authors.affiliation: Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Clinical Sciences Building 2, City Hospital, Nottingham, UK, NG5 1 PB; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177, Stockholm, Sweden. Electronic address: david.humes@nottingham.ac.uk.
authors.forename: David J
authors.initials: DJ
authors.lastname: Humes
authors.affiliation: Unit of Paediatric Surgery, Department of Women's and Children's Health, Karolinska Institutet, 17177 Stockholm, Sweden. Electronic address: Agneta.Nordenskjold@ki.se.
authors.forename: Agneta
authors.initials: A
authors.lastname: Nordenskjöld
authors.affiliation: Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Clinical Sciences Building 2, City Hospital, Nottingham, UK, NG5 1 PB. Electronic address: alex.walker@nottingham.ac.uk.
authors.forename: Alex J
authors.initials: AJ
authors.lastname: Walker
authors.affiliation: Division of Epidemiology and Public Health, School of Medicine, University of Nottingham, Clinical Sciences Building 2, City Hospital, Nottingham, UK, NG5 1 PB. Electronic address: joe.west@nottingham.ac.uk.
authors.forename: Joe
authors.initials: J
authors.lastname: West
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, 17177, Stockholm, Sweden; Department of Paediatrics, Örebro University Hospital, 70185 Örebro, Sweden. Electronic address: jonasludvigsson@yahoo.com.
authors.forename: Jonas F
authors.initials: JF
authors.lastname: Ludvigsson
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D011183:Postoperative Complications / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012307:Risk Factors; D013514:Surgical Procedures, Operative; D054556:Venous Thromboembolism / Q000453:epidemiology*
keywords: Deep vein thrombosis; General surgery; Pulmonary embolus