title: Role of neutrophil to lymphocyte and monocyte to lymphocyte ratios in the diagnosis of bacterial infection in patients with fever.
abstract: OBJECTIVE
  To study the role of the neutrophil:lymphocyte ratio (NLR) and monocyte:lymphocyte ratio (MLR) in discriminating between different patient groups hospitalized for fever due to infection and those without infection.
  
  
  METHODS
  For 299 patients admitted to hospital for fever with unknown cause, a number of characteristics including NLR and MLR were recorded. These characteristics were used in a multiple multinomial regression analysis to estimate the probability of a final diagnostic group of bacterial, viral, clinically confirmed, or no infection.
  
  
  RESULTS
  Both NLR and MLR significantly predicted final diagnostic group. Being highly correlated, however, both variables could not be retained in the same model. Both variables also interacted significantly with duration of fever. Generally, higher values of NLR and MLR indicated larger probabilities for bacterial infection and low probabilities for viral infection. Patients with septicemia had significantly higher NLR compared to patients with other bacterial infections with fever for less than one week. White blood cell counts, neutrophil counts, and C-reactive proteins did not differ significantly between septicemia and the other bacterial infection groups.
  
  
  CONCLUSIONS
  NLR is a more useful diagnostic tool to identify patients with septicemia than other more commonly used diagnostic blood tests. NLR and MLR may be useful in the diagnosis of bacterial infection among patients hospitalized for fever.
authors.affiliation: Department of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021, Bergen, Norway. are.nass@k2.uib.no.
authors.forename: Are
authors.identifier: http://orcid.org/0000-0002-5769-1995
authors.initials: A
authors.lastname: Naess
authors.affiliation: Department of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021, Bergen, Norway.|Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Siri Saervold
authors.initials: SS
authors.lastname: Nilssen
authors.affiliation: Department of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021, Bergen, Norway.|Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Reidun
authors.initials: R
authors.lastname: Mo
authors.affiliation: Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway.|Lifestyle Epidemiology Research Group, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: Geir Egil
authors.initials: GE
authors.lastname: Eide
authors.affiliation: Department of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021, Bergen, Norway.|Department of Medicine, Haukeland University Hospital, Bergen, Norway.
authors.forename: Haakon
authors.initials: H
authors.lastname: Sjursen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000175:diagnosis* / Q000276:immunology; D005260:Female; D005334:Fever / Q000453:epidemiology* / Q000209:etiology / Q000382:microbiology; D006760:Hospitalization; D006785:Hospitals, University; D006801:Humans; D007958:Leukocyte Count; D008214:Lymphocytes / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D015999:Multivariate Analysis; D009504:Neutrophils / Q000276:immunology*; D009664:Norway / Q000453:epidemiology; D014777:Virus Diseases / Q000175:diagnosis / Q000276:immunology; D055815:Young Adult
keywords: Fever; Infections; Monocyte:lymphocyte ratio (MLR); Neutrophil:lymphocyte ratio (NLR)