title: Validity of procalcitonin for the diagnosis of bacterial infection in elderly patients.
abstract: BACKGROUND
  PCT has been consolidated as a key tool in the diagnosis of bacterial infections in general population. Few studies have been conducted to determine the applicability of this test in elderly patients.
  
  
  METHODS
  Study of validity of PCT on elderly patients. Two groups were formed; the first group was formed by patients aged 75 years or older, under bacterial infection criteria and PCT on the initial Lab test. The second group was formed by patients aged 75 years or older with any noninfectious disease; these patients were asked PCT in the initial Lab test. Sensitivity, specificity, positive and negative likelihood ratio were calculated.
  
  
  RESULTS
  161 patients were included, 95 with probable bacterial infection and 66 without infection. Patients with probable bacterial infection criteria, 72% of them had PCT >0.5 ng/mL. Patients without infection, 8% of the patients had PCT >0.5 ng/mL. Sensitivity and specificity of PCT to bacterial infection with the cutoff value of 0.5 ng/mL was 72% and 92%, respectively.
  
  
  CONCLUSIONS
  PCT can be used in elderly patients to diagnose bacterial infections because it has proved good sensitivity and high specificity.
authors.affiliation: Department of Internal Medicine, San Pedro Hospital, Logroño, Spain. Electronic address: jmgomez@riojasalud.es.
authors.forename: Juan Manuel
authors.initials: JM
authors.lastname: Gómez-Cerquera
authors.affiliation: Department of Internal Medicine, San Pedro Hospital, Logroño, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: Daroca-Pérez
authors.affiliation: Department of Internal Medicine, San Pedro Hospital, Logroño, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Baeza-Trinidad
authors.affiliation: Department of Internal Medicine, San Pedro Hospital, Logroño, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Casañas-Martinez
authors.affiliation: Department of Internal Medicine, San Pedro Hospital, Logroño, Spain.
authors.forename: Jose Daniel
authors.initials: JD
authors.lastname: Mosquera-Lozano
authors.affiliation: Department of Epidemiology, Logroño, Spain.
authors.forename: Enrique
authors.initials: E
authors.lastname: Ramalle-Gómara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001424:Bacterial Infections / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers; D002116:Calcitonin / Q000097:blood*; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D009422:Nervous System Diseases / Q000453:epidemiology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood
chemical_list: D015415:Biomarkers; D002116:Calcitonin
keywords: Bacterial infection; Elderly patients; Infección bacteriana; Pacientes ancianos; Procalcitonin; Procalcitonina