title: Increased short- and long-term mortality among patients with infectious spondylodiscitis compared with a reference population.
abstract: BACKGROUND
  Information on short- and especially long-term mortality among patients with infectious spondylodiscitis is sparse.
  
  
  OBJECTIVE
  To analyze mortality, factors associated with death, and cause-specific mortality rates among patients with infectious nonpostoperative spondylodiscitis.
  
  
  METHODS
  A case-cohort study.
  
  
  METHODS
  We identified all patients aged 18 years or older treated for infectious spondylodiscitis from January 1994 to May 2009 at hospitals in Funen County, Denmark.
  
  
  METHODS
  Overall and cause-specific mortality.
  
  
  METHODS
  Mortality rates among patients were compared with rates among a reference population using Kaplan-Meier plots and mortality rate ratios (MRRs). Short-term mortality was defined as deaths within first year after admission and long-term mortality was deaths thereafter. Factors associated with death were determined.
  
  
  RESULTS
  Among 298 identified patients, 61 (20%) died within the first year. Adjusted MRRs were 16.8 (95% confidence interval: 9.9-28.5) for 0 to 90 days; 4.2 (2.5-7.0) for 91 to 365 days; 2.2 (1.6-2.9) for 1 to 4 years; and 1.7 (1.2-2.5) for 5 to 14 years. Mortality rate ratios stratified on microbiological etiology were 8.8 (3.3-22.1) for 0 to 90 days; 1.4 (0.3-5.8) for 91 to 365 days; 3.2 (2.0-5.1) for 1 to 4 years; and 1.1 (0.5-2.4) for 5 to 14 years for unknown etiology and 24.0 (13.0-44.2) for 0 to 90 days; 6.0 (3.1-11.5) for 91 to 365 days; 1.9 (1.1-3.2) for 1 to 4 years; and 2.7 (1.5-4.7) for 5 to 14 years among Staphylococcus aureus infections. The main factors associated with short-term mortality were severe neurologic deficits at the time of admission, epidural abscess, and comorbidities. Long-term mortality seemed independent of microbiological etiology.
  
  
  CONCLUSIONS
  Mortality remained high the first year after admission and thereafter decreased with time to a level close to the reference population. Short-term mortality was especially related to infection with abscess formation and neurologic deficits and long-term mortality was related to alcohol dependency.
authors.affiliation: Institute of Clinical Research, University of Southern Denmark, Winsløwparken 19/3, 5000 Odense C, Denmark; Department of Infectious Diseases, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark. Electronic address: michala.kehrer@rsyd.dk.
authors.forename: Michala
authors.initials: M
authors.lastname: Kehrer
authors.affiliation: Institute of Clinical Research, University of Southern Denmark, Winsløwparken 19/3, 5000 Odense C, Denmark; Department of Infectious Diseases, Odense University Hospital, Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: Court
authors.initials: C
authors.lastname: Pedersen
authors.affiliation: Department of Clinical Microbiology, Odense University Hospital, J.B. Winsløws Vej 21, 2, 5000 Odense C, Denmark.
authors.forename: Thøger Gorm
authors.initials: TG
authors.lastname: Jensen
authors.affiliation: Research Unit of Clinical Pharmacology, University of Southern Denmark, Winsløvparken 10, 3., 5000 C, Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Hallas
authors.affiliation: Institute of Clinical Research, University of Southern Denmark, Winsløwparken 19/3, 5000 Odense C, Denmark; Department of Emergency Medicine, Odense University Hospital. Sdr. Boulevard 29, 5000 Odense C, Denmark.
authors.forename: Annmarie T
authors.initials: AT
authors.lastname: Lassen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003718:Denmark / Q000453:epidemiology; D015299:Discitis / Q000401:mortality*; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000401:mortality*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D055815:Young Adult
keywords: Bone diseases; Cause of death; Factors associated with death; Infectious; Mortality; Prognosis; Spine; Vertebral osteomyelitis