title: Epidemiology and outcome of sepsis in adult patients with Streptococcus pneumoniae infection in a Norwegian county 1993-2011: an observational study.
abstract: Invasive pneumococcal disease (IPD) is responsible for significant mortality and morbidity worldwide. There are however few longitudinal studies on the changes in case fatality rate of IPD in recent years. We carried out a prospective observational study of patients with IPD in Nord Trøndelag county in Norway from 1993 to 2011 to study the clinical variables and disease outcome. The main outcome was all-cause mortality after 30 and 90 days.
  
  
  
  Patients with positive blood cultures were registered prospectively by the microbiology laboratory and clinical variables were registered retrospectively from patients' hospital records. The severity of sepsis was assigned according to the 2001 International Sepsis Definition Conference criteria. The association between mortality and predictive factors was studied using a logistic regression model.
  
  
  
  The total number of patients was 414 with mean age of 67 years and 53 % were male. Comorbidity was assessed by the Charlson Comorbidity Index (CCI). A CCI-score of 0 was registered in 144 patients (34.8 %), whereas 190 had a score of 1-2 (45.9 %) and 80 (19.3 %) had a score ≥3. 68.8 % of the patients received appropriate antibiotics within the first 6 h. The 30-day mortality risk increased by age and was 3-fold higher for patients aged ≥80 years (24.9, 95 % CI 16.4-33.4 %) compared to patients aged <70 (8.0, 95 % CI 3.5-12.4 %). 110 patients, (26.6 %) had severe sepsis and 37 (8.9 %) had septic shock. The 30 day all-cause mortality risk for those with sepsis without organ failure was 5.4 % (95 % CI 2.7-8.0 %), 20.2 % (95 % CI 13.5-27.4 %) for those with severe sepsis and 35.0 % (95 % CI 21.6-49.0 %) for those with septic shock. The mortality risk did not differ between the first and the second halves of the study period with a 30-day mortality risk of 13.5 % (95 % CI 7.9-19.2 %) for 1993-2002 versus 11.8 % (95 % CI 8.2-15.3 %) for 2003-2011.
  
  
  
  IPD carries a high mortality despite early and appropriate antibiotics in most cases. We found no substantial decrease in case fatality rate during the study period of 18 years. Older age and higher severity of disease were important risk factors for death in IPD.
authors.affiliation: Clinic of Anaesthesia and Intensive Care, St Olav University Hospital, Trondheim, Norway. asa.askim@ntnu.no.|Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. asa.askim@ntnu.no.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway. asa.askim@ntnu.no.|Faculty of medicine, Department of Circulation and Medical Imaging, Po box 8905, N-7491, Trondheim, Norway. asa.askim@ntnu.no.
authors.forename: Åsa
authors.initials: Å
authors.lastname: Askim
authors.affiliation: Centre of Molecular Inflammation Research Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|Department of Medicine, Levanger Hospital, Nord-Trøndelag Health Trust, Levanger, Norway.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Arne
authors.initials: A
authors.lastname: Mehl
authors.affiliation: Centre of Molecular Inflammation Research Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|Department of Medicine, Levanger Hospital, Nord-Trøndelag Health Trust, Levanger, Norway.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Julie
authors.initials: J
authors.lastname: Paulsen
authors.affiliation: Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, CT, USA.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: DeWan
authors.affiliation: Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Didrik F
authors.initials: DF
authors.lastname: Vestrheim
authors.affiliation: Department of Public Health, Norwegian University of Science and Technology, Trondheim, Norway.|Department of Endocrinology, St Olav University Hospital, Trondheim, Norway.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Bjørn Olav
authors.initials: BO
authors.lastname: Åsvold
authors.affiliation: Centre of Molecular Inflammation Research Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway.|Department of Infectious Diseases, St Olav University Hospital, Trondheim, Norway.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Jan Kristian
authors.initials: JK
authors.lastname: Damås
authors.affiliation: Clinic of Anaesthesia and Intensive Care, St Olav University Hospital, Trondheim, Norway.|Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.|Middle Norway Sepsis Research Center, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Erik
authors.initials: E
authors.lastname: Solligård
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D015897:Comorbidity; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011008:Pneumococcal Infections / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000150:complications / Q000453:epidemiology* / Q000382:microbiology / Q000401:mortality; D016019:Survival Analysis
chemical_list: D000900:Anti-Bacterial Agents
keywords: Bacteremia; Sepsis; Streptococcus pneumoniae