title: Validation of Thwaites Index for diagnosing tuberculous meningitis in a Colombian population.
abstract: OBJECTIVE
  To determine the diagnostic accuracy of Thwaites Index (TI) in a Colombian population to distinguish meningeal tuberculosis (MTB) from bacterial meningitis (BM) and from non-tuberculous meningitis. Exploratory analyses were conducted to assess the TI's validity for patients with human immunodeficiency virus (HIV) and children above six-years-old.
  
  
  METHODS
  The study included 527 patients, the TI was calculated and results compared with those of a reference standard established by expert neurologists. Sensitivity, specificity, area under the curve of receiver-operator characteristics (AUC-ROC) and likelihood ratios were calculated.
  
  
  RESULTS
  The AUC-ROC to distinguish MTB from non-tuberculous meningitis was 0.72 (95% CI: 0.67-0.77) for HIV negative adults. AUC-ROC was 0.62 (95% CI: 0.50-0.74) for HIV positive adults and 0.83 (95% CI: 0.68-0.97) for children. For distinguishing MTB from BM the AUC-ROC was 0.78 (95% CI: 0.73-0.83); furthermore, the AUC-ROC was 0.57 (95% CI: 0.31-0.83) for HIV positive adults and 0.86 (95% CI: 0.73-0.99) for children.
  
  
  CONCLUSIONS
  The TI was sensitive but not specific when used to distinguish MTB from BM in HIV negative adults. In HIV positive adults the index had low diagnostic accuracy. Moreover, the TI showed discrimination capability for children over 6years; however, research with larger samples is required in these.
authors: Neurology Section, Department of Internal Medicine, Faculty of Medicine, University of Antioquia, Bloque 6, Calle 64 # 51 D - 154, Medellín, Colombia.
authors: Juan Sebastián
authors: JS
authors: Saavedra
authors: Neurology Section, Department of Internal Medicine, Faculty of Medicine, University of Antioquia, Bloque 6, Calle 64 # 51 D - 154, Medellín, Colombia.
authors: Sebastián
authors: S
authors: Urrego
authors: Neurology Section, Department of Internal Medicine, Faculty of Medicine, University of Antioquia, Bloque 6, Calle 64 # 51 D - 154, Medellín, Colombia.
authors: María Eugenia
authors: ME
authors: Toro
authors: Neurology Section, Department of Internal Medicine, Faculty of Medicine, University of Antioquia, Bloque 6, Calle 64 # 51 D - 154, Medellín, Colombia.
authors: Carlos Santiago
authors: CS
authors: Uribe
authors: Clinical Epidemiology Academic Group (GRAEPIC), Faculty of Medicine, University of Antioquia, Carrera 51 D # 62-29, Edificio Manuel Uribe Ángel, tercer piso, Medellín, Colombia.
authors: Jenny
authors: J
authors: García
authors: Instituto Neurológico de Colombia, Calle 55 # 46-36, Medellín, Colombia.
authors: Olga
authors: O
authors: Hernández
authors: Department of Pathology, Faculty of Medicine, University of Antioquia, Bloque 13, Calle 64 N°51 D - 154, Medellín, Colombia.
authors: Juan Carlos
authors: JC
authors: Arango
authors: IPS Universitaria Clínica León XIII, Calle 69 # 51 C 24, Medellín, Colombia.
authors: Ángela Beatriz
authors: ÁB
authors: Pérez
authors: Hospital Pablo Tobón Uribe, Calle 78B # 69-240, Medellín, Colombia.
authors: Andrés
authors: A
authors: Franco
authors: Neurology Section, Department of Internal Medicine, Faculty of Medicine, University of Antioquia, Bloque 6, Calle 64 # 51 D - 154, Medellín, Colombia.
authors: Isabel Cristina
authors: IC
authors: Vélez
authors: MICROBA, School of Microbiology, University of Antioquia, Calle 67 # 53-108 Bloque 5, Medellín, Colombia. Electronic address: helena.delcorral@udea.edu.co.
authors: Helena
authors: H
authors: Del Corral
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002648:Child; D003105:Colombia; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D015658:HIV Infections / Q000134:cerebrospinal fluid / Q000150:complications; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D014390:Tuberculosis, Meningeal / Q000134:cerebrospinal fluid* / Q000150:complications / Q000175:diagnosis*; D055815:Young Adult
chemical_list: D015415:Biomarkers
keywords: Bacterial meningitis; Diagnosis; Meningeal tuberculosis; ROC curve; Sensitivity; Specificity