title: Validation of reoperations due to infection in the Swedish Hip Arthroplasty Register.
abstract: BACKGROUND
  Complete or almost complete recording of reoperations is essential to enable a correct interpretation of data in arthroplasty registers. The completeness of recordings due to infection is unknown in the Swedish Hip Arthroplasty Register (SHAR). We therefore used a combination of data from the Swedish Prescribed Drug Register (SPDR) and studies of medical records to validate the data of reoperations due to infection in the SHAR.
  
  
  METHODS
  All patients registered for a primary Total Hip Replacement (THR) in the SHAR between July 1, 2005 and December 31, 2008 were selected for the study (45,531 patients with 49,219 THRs) and were matched with the SPDR. All patients with a minimum of 4 weeks of continuous outpatient antibiotic treatment within 2 years after their primary THR (1,989 patients, with 2,219 THRs) were selected for a medical records review to find the THRs reoperated due to infection.
  
  
  RESULTS
  599 (1.3%) of the THRs had been reoperated within 2 years after the index operation and in 47.4% of these the prosthesis had been revised or extracted. 400 of the THRs were registered for a reoperation in the SHAR resulting in a completeness of 67%.
  
  
  CONCLUSIONS
  The completeness of registration due to early infection after THR questions whether the SHAR reoperation data can be used in order to evaluate changes in postoperative infection rates.
authors.affiliation: Department of Molecular Medicine and Surgery, Section of Orthopaedics, Karolinska Institutet, Stockholm, Sweden. viktor.lindgren@karolinska.se.
authors.forename: J Viktor
authors.initials: JV
authors.lastname: Lindgren
authors.forename: Max
authors.initials: M
authors.lastname: Gordon
authors.forename: Per
authors.initials: P
authors.lastname: Wretenberg
authors.forename: Johan
authors.initials: J
authors.lastname: Kärrholm
authors.forename: Göran
authors.initials: G
authors.lastname: Garellick
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D012042:Registries / Q000592:standards*; D012086:Reoperation / Q000592:standards; D011795:Surveys and Questionnaires / Q000592:standards*; D013548:Sweden / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents