title: Surgical site infections after hip arthroplasty in Norway, 2005-2011: influence of duration and intensity of postdischarge surveillance.
abstract: BACKGROUND
  Most surgical site infections (SSIs) after hip arthroplasty are detected after a patient is discharged from hospital, making postdischarge surveillance (PDS) an important component in surveillance systems. We investigated how long it was necessary to monitor hip arthroplasty patients for SSIs after hospital discharge and if passive PDS through readmissions could replace active PDS by patient questionnaire in detecting SSIs.
  
  
  METHODS
  We used data from the Norwegian surveillance system from 2005-2011, which has active 1-year PDS, to investigate proportions of SSIs found at different time intervals after surgery and whether these SSIs could have been detected through passive PDS by investigating the proportion of patients with SSIs that were readmitted.
  
  
  RESULTS
  We found that 79% of all SSIs and 82% of deep SSIs were detected after hospital discharge. 95% of deep SSIs were detected within 90 days after surgery. 14% of the deep SSIs were detected beyond 30 days after surgery, and all of these patients were readmitted because of their SSI and thus could have been detected by passive PDS.
  
  
  CONCLUSIONS
  Our data suggest that most deep SSIs are detected within 90 days and that passive PDS beyond 30 days after surgery may replace active PDS without reducing sensitivity.
authors: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, Oslo, Norway. Electronic address: hege.line.lower@fhi.no.
authors: Hege Line
authors: HL
authors: Løwer
authors: Department of Orthopedic Surgery, The Norwegian Arthroplasty Register, Haukeland University Hospital, Bergen, Norway.
authors: Håvard
authors: H
authors: Dale
authors: Department of Infectious Disease Epidemiology, Norwegian Institute of Public Health, Oslo, Norway.
authors: Hanne-Merete
authors: HM
authors: Eriksen
authors: Epidemi, Lasarettet, Kristiansand, Norway.
authors: Preben
authors: P
authors: Aavitsland
authors: Faculty of Health Sciences, Department of Community Medicine, Research Group Epidemiology of Chronic Diseases, UiT The Arctic University of Norway, Tromsø, Norway.
authors: Finn Egil
authors: FE
authors: Skjeldestad
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D005500:Follow-Up Studies; D006801:Humans; D007902:Length of Stay; D009664:Norway / Q000453:epidemiology; D010351:Patient Discharge; D011159:Population Surveillance; D011182:Postoperative Care; D011183:Postoperative Complications / Q000453:epidemiology* / Q000382:microbiology; D012307:Risk Factors; D013530:Surgical Wound Infection / Q000175:diagnosis* / Q000453:epidemiology*; D011795:Surveys and Questionnaires; D013997:Time Factors
keywords: Electronic; Length of stay; Readmission; Surgical wound infection