Long-term mortality after Staphylococcus aureus spondylodiscitis: a Danish nationwide population-based cohort study.
OBJECTIVE
To determine the long-term mortality and the causes of death after Staphylococcus aureus spondylodiscitis.


METHODS
Nationwide, population-based cohort study using national registries of adults diagnosed with non postoperative S. aureus spondylodiscitis from 1994-2009 and alive 1 year after diagnosis (n Z 313). A comparison cohort from the background population individually matched on sex and age was identified (n Z 1565). Kaplan-Meier survival curves were constructed and Poisson regression analyses used to estimate mortality rate ratios (MRR) adjusted for comorbidity.


RESULTS
88 patients (28.1%) and 267 individuals from the population-based comparison cohort (17.1%) died. Un-adjusted MRR for S. aureus spondylodiscitis patients was 1.77 (95% CI, 1.39-2.25) and 1.32 (95% CI, 1.02-1.71) after adjustment for comorbidity. We observed increased mortality due to infectious (MRR 8.57; 95% CI, 2.80-26.20), endocrine (MRR 3.57; 95%CI, 1.01-12.66), cardiovascular (MRR 1.59; 95% CI, 1.02-2.49), gastrointestinal (MRR 3.21; 95% CI, 1.178.84) and alcohol and drug abuse-related (MRR 10.71; 95% CI, 3.23-35.58) diseases.


CONCLUSIONS
Patients diagnosed with S. aureus spondylodiscitis have substantially increased long-term mortality, mainly due to comorbidity. To improve survival after S. aureus spondylodiscitis these patients should be screened for comorbidity and substance abuse predisposing to the disease [corrected].
Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark. Electronic address: theisaagaard@gmail.com.
Theis
T
Aagaard
Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
Casper
C
Roed
The Staphylococcus Laboratory, Statens Serum Institut, Copenhagen, Denmark.
Anders R
AR
Larsen
The Staphylococcus Laboratory, Statens Serum Institut, Copenhagen, Denmark.
Andreas
A
Petersen
Department of Orthopaedic Surgery, Spine Unit, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
Benny
B
Dahl
Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
Peter
P
Skinhøj
Department of Infectious Diseases, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, 2100 Copenhagen, Denmark.
Niels
N
Obel
D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality; D016022:Case-Control Studies; D002423:Cause of Death; D015331:Cohort Studies; D003718:Denmark / Q000453:epidemiology; D015299:Discitis / Q000382:microbiology* / Q000401:mortality*; D004700:Endocrine System Diseases / Q000401:mortality; D005260:Female; D005767:Gastrointestinal Diseases / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D012042:Registries; D013203:Staphylococcal Infections / Q000401:mortality*; D013211:Staphylococcus aureus; D019966:Substance-Related Disorders / Q000401:mortality; D013997:Time Factors
Long-term mortality; Prognosis; Spondylodiscitis; Staphylococcus aureus; Vertebral osteomyelitis