title: Has the rate of in-hospital infections after total joint arthroplasty decreased?
abstract: BACKGROUND
  Although infections are a major cause of morbidity and mortality after total joint arthroplasty (TJA), little is known about nationwide epidemiology and trends of infections after TJA.
  
  
  OBJECTIVE
  We therefore determined (1) trends of postoperative pneumonia, urinary tract infection (UTI), surgical site infection (SSI), sepsis, and severe sepsis after TJA; (2) risk factors of these infections; (3) effect of these infections on length of stay (LOS) and hospital charges; and (4) the infection-related mortality rate and its predictors.
  
  
  METHODS
  The International Classification of Diseases, 9th Revision codes were used to identify patients who underwent TJA and were diagnosed with aforementioned infections during hospitalization in the Nationwide Inpatient Sample database from 2002 to 2010. Multivariate analysis was performed to identify risk factors of these infections.
  
  
  RESULTS
  Rates of pneumonia, UTI, SSI, sepsis, and severe sepsis were 0.74%, 3.26%, 0.31%, 0.25%, and 0.15%, respectively. Number of comorbidities and type of TJA were independent predictors of infection. Mortality decreased during the study period (odds ratio, 0.87; 95% confidence interval, 0.86-0.89). The median LOS was 3 days without complications but increased in the presence of SSI (median, 7 days), sepsis (median, 12 days), and severe sepsis (median, 15 days). Occurrence of pneumonia, sepsis, and severe sepsis increased risk of mortality 5.2, 8.5, and 66.2 times, respectively.
  
  
  CONCLUSIONS
  Rates of UTI, pneumonia, and SSI but not sepsis and severe sepsis are apparently decreasing. The likelihood of infection is increasing with number of comorbidities and revision surgeries. Rate of sepsis-related mortality is also decreasing.
  
  
  METHODS
  Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: The Rothman Institute of Orthopedics at Thomas Jefferson Hospital, 925 Chestnut Street, Philadelphia, PA, 19107, USA.
authors.forename: Mohammad R
authors.initials: MR
authors.lastname: Rasouli
authors.forename: Mitchell Gil
authors.initials: MG
authors.lastname: Maltenfort
authors.forename: James J
authors.initials: JJ
authors.lastname: Purtill
authors.forename: William J
authors.initials: WJ
authors.lastname: Hozack
authors.forename: Javad
authors.initials: J
authors.lastname: Parvizi
mesh_terms: D000328:Adult; D000368:Aged; D019643:Arthroplasty, Replacement / Q000009:adverse effects*; D003428:Cross Infection / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D005260:Female; D006760:Hospitalization; D006801:Humans; D015994:Incidence; D007595:Joint Prosthesis / Q000009:adverse effects; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011014:Pneumonia / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D012307:Risk Factors; D018805:Sepsis / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D013530:Surgical Wound Infection / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D014552:Urinary Tract Infections / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality