title: Assessment of previous tuberculosis status using questionnaires, chest X-rays and computed tomography scans.
abstract: METHODS
  Accurate diagnosis of previous pulmonary tuberculosis disease (PPTB) status is important clinically and in research. Reliable records of bacteriologically confirmed tuberculosis (TB) are frequently unavailable.
  
  
  OBJECTIVE
  To evaluate the use of questionnaires and chest imaging to determine PPTB status in a high TB prevalence population.
  
  
  METHODS
  PPTB status was assessed using two questionnaires, chest X-ray (CXR) and high-resolution chest computed tomography (CT) scans reported by experienced readers. The study population comprised adults aged >40 years diagnosed with obstructive lung disease in a community-based prevalence survey.
  
  
  RESULTS
  The Burden of Obstructive Lung Disease (BOLD) questionnaire and a second comprehensive questionnaire (PTbQ) provided a history of PPTB in respectively 38% (n = 41) and 36.4% (n = 39) of 107 participants. On CXR, 43.3% (45/104) had evidence of PPTB, with good inter-reader agreement (κ = 0.73). Changes compatible with PPTB were identified on chest CT in 68.3% (71/104) of the subjects. Questionnaire and CXR had negative predictive values for PPTB of 48% and 47%, respectively, compared to a composite definition.
  
  
  CONCLUSIONS
  Both questionnaire and CXR markedly underestimate the prevalence of previous TB in patients with chronic obstructive pulmonary disease. The combination of a structured questionnaire and CT scan is more useful when a diagnosis of PPTB needs to be ruled out.
authors.affiliation: Division of Pulmonology, Department of Medicine, Stellenbosch University and University of Cape Town (UCT) Lung Institute, Cape Town, South Africa.
authors.forename: B W
authors.initials: BW
authors.lastname: Allwood
authors.affiliation: David Geffen School of Medicine, University of California, Los Angeles, California, USA.
authors.forename: J
authors.initials: J
authors.lastname: Goldin
authors.affiliation: Department of Radiology, Groote Schuur Hospital & UCT, Cape Town, South Africa.
authors.forename: Q
authors.initials: Q
authors.lastname: Said-Hartley
authors.affiliation: Division of Pulmonology, Department of Medicine, University of Cape Town & UCT Lung Institute, Cape Town, South Africa.
authors.forename: R N
authors.initials: RN
authors.lastname: van Zyl-Smit
authors.affiliation: Division of Pulmonology, Department of Medicine, University of Cape Town & UCT Lung Institute, Cape Town, South Africa.
authors.forename: G
authors.initials: G
authors.lastname: Calligaro
authors.affiliation: Division of Pulmonology, Department of Medicine, University of Cape Town & UCT Lung Institute, Cape Town, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: Esmail
authors.affiliation: Desmond Tutu TB Centre, Department of Paediatrics and Child Health, Stellenbosch University, Cape Town, South Africa.
authors.forename: N
authors.initials: N
authors.lastname: Beyers
authors.affiliation: Division of Pulmonology, Department of Medicine, University of Cape Town & UCT Lung Institute, Cape Town, South Africa.
authors.forename: E D
authors.initials: ED
authors.lastname: Bateman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications; D013902:Radiography, Thoracic; D013183:Sputum / Q000382:microbiology; D011795:Surveys and Questionnaires; D014057:Tomography, X-Ray Computed; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging* / Q000453:epidemiology*