title: One-year incidence of prosthetic joint infection in total hip arthroplasty: a cohort study with linkage of the Danish Hip Arthroplasty Register and Danish Microbiology Databases.
abstract: To examine the trend of Prosthetic Joint Infections (PJI) following primary total hip arthroplasty (THA) and the antimicrobial resistance of the bacteria causing these infections.
  
  
  
  We identified a population-based cohort of patients in the Danish Hip Arthroplasty Register (DHR) who had primary THA and received their surgery in Jutland or Funen between 2005 and 2014. We followed the patients until revision, emigration, death, or up to 1-year of follow-up. Data from the DHR were combined with those from microbiology databases, the National Register of Patients, and the Civil Registration System. We estimated the cumulative 1-year incidence of PJI for two 5-year periods; 2005-2009 and 2010-2014. The hazard ratio of PJI as a measure of relative risk after adjusting for multiple risk factors was calculated.
  
  
  
  Of 48,867 primary THAs identified, 1120 underwent revision within 1 year. Of these, 271 were due to PJI. The incidence of PJI was 0.53% (95% confidence interval (CI): 0.44; 0.63) during 2005-2009 and 0.57% (95% CI: 0.49; 0.67) during 2010-2014. The adjusted relative risk was 1.05 (95% CI: 0.82; 1.34) for the 2010-2014 period vs the 2005-2009 period. The most common micro-organisms identified in the 271 PJI were Staphylococcus aureus (36%) and coagulase-negative staphylococci (CoNS) (33%); others commonly identified included Enterobacteriaceae, enterococci, and streptococci. Antimicrobial resistance to beta-lactams and gentamicin did not change during the study period.
  
  
  
  The risk of PJI within 1-year after primary THA and the antimicrobial resistance of the most prevalent bacteria remained unchanged during the 2005-2014 study period.
authors.affiliation: Department of Orthopaedics, Kolding Hospital - a Part of Lillebaelt Hospital, Denmark; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark; Institute of Clinical Research, University of Southern Denmark, Denmark. Electronic address: per.hviid.gundtoft@rsyd.dk.
authors.forename: P H
authors.initials: PH
authors.lastname: Gundtoft
authors.affiliation: Clinical Epidemiology, Aarhus University Hospital, Denmark. Electronic address: abp@dce.au.dk.
authors.forename: A B
authors.initials: AB
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Microbiology, Aalborg University Hospital, Aalborg, Denmark; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark. Electronic address: hcs@rn.dk.
authors.forename: H C
authors.initials: HC
authors.lastname: Schønheyder
authors.affiliation: Department of Clinical Microbiology, Vejle Hospital - a part of Lillebaelt Hospital, Vejle, Denmark; Institute of Regional Health Research, University of Southern Denmark, Denmark. Electronic address: Jens.Kjoelseth.Moeller@rsyd.dk.
authors.forename: J K
authors.initials: JK
authors.lastname: Møller
authors.affiliation: Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark; Institute of Clinical Research, University of Southern Denmark, Denmark; Danish Hip Arthroplasty Register(a), Denmark. Electronic address: Soeren.Overgaard@rsyd.dk.
authors.forename: S
authors.initials: S
authors.lastname: Overgaard
mesh_terms: D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D015331:Cohort Studies; D003131:Combined Modality Therapy; D016208:Databases, Factual; D003718:Denmark; D020878:Device Removal; D005260:Female; D005500:Follow-Up Studies; D006622:Hip Prosthesis / Q000009:adverse effects / Q000382:microbiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000601:surgery; D011300:Preoperative Care / Q000379:methods; D016459:Prosthesis-Related Infections / Q000453:epidemiology* / Q000382:microbiology / Q000628:therapy*; D012042:Registries; D012086:Reoperation / Q000379:methods; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobial resistance; Epidemiology; Incidence; Microbiology; Prosthetic joint infection