title: Validation of oesophageal cancer surgery data in the Swedish Patient Registry.
abstract: BACKGROUND
  The Swedish Patient Registry provides data about diagnoses and surgical procedures for research purposes. There are, however, almost no validation studies of the data on surgical procedures, and none of oesophageal cancer surgery.
  
  
  METHODS
  This was a validation study of the accuracy of codes representing oesophageal cancer resection, surgical approach and oesophageal substitute in the Swedish Patient Registry during the period 1987-2005. The registered data were compared with a thorough review of the corresponding operation charts collected from medical records.
  
  
  RESULTS
  Among 1358 patients with a code representing oesophageal resection in the Patient Registry, the positive predictive value was 99.6%. The dominant surgical procedures in terms of surgical approach (transthoracic) and type of oesophageal substitute (gastric conduit) had positive predictive values of 99.8% and 99.4%, respectively. The more rare procedures with regards to approach (transhiatal) and substitute (bowel) had lower positive predictive values of 68.8% and 68.5%, respectively.
  
  
  CONCLUSIONS
  The high accuracy of the data regarding oesophageal cancer resection in the Swedish Patient Registry stresses its appropriateness for research purposes.
authors.affiliation: Upper Gastrointestinal Research, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. katarinalagergren@hotmail.com
authors.forename: Katarina
authors.initials: K
authors.lastname: Lagergren
authors.forename: Maryam
authors.initials: M
authors.lastname: Derogar
mesh_terms: D000230:Adenocarcinoma / Q000453:epidemiology / Q000601:surgery; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology / Q000601:surgery; D059019:Clinical Coding / Q000592:standards*; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D012042:Registries / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D013548:Sweden / Q000453:epidemiology