title: Accuracy of non-invasive 13C-Urea Breath Test compared to invasive tests for Helicobacter pylori detection.
abstract: OBJECTIVE
  To compare the sensitivity, specificity and Positive Predictive Value (PPV) of histology, Campylobacter-Like Organism (CLO) test, culture and 13C-Urea Breath Test (UBT) for the diagnosis of Helicobacter pylori infection.
  
  
  METHODS
  Descriptive study.
  
  
  METHODS
  District Headquarter Hospital, Rawalpindi, Military Hospital, Rawalpindi and Pakistan Institute of Science and Technology (PINSTECH), Nilore, Islamabad from June 2002 to 2003.
  
  
  METHODS
  Three mucosal biopsy specimens were obtained during endoscopy of 90 symptomatic patients. Histology, CLO test and culture were performed on these specimens. Breath samples for 13C-UBT were collected and sent to RIAD, PINSTECH on the same day for isotope ratio mass spectrometry. For analysis purpose, each of the tests was fixed as the gold standard in turn and the others were then compared against it. In addition, any two as well as any three positive tests were then set as the gold standard and the other tests compared against them to calculate the sensitivity, specificity, accuracy and PPV of other tests.
  
  
  RESULTS
  Urea breath test had the highest sensitivity, ranging from 95 to 100%, against all the gold standards with specificity ranging from 55 to 100%, whereas the sensitivity of histological examination was around 98% but it had comparatively lower specificity (49-89%). The CLO test had a sensitivity range of 86-100% and specificity of 67-100%. Culture had the minimum sensitivity (59-70%) but had highest specificity (96-100%) against all the gold standards. Age and gender had no effect on p-value of each test or in combination.
  
  
  CONCLUSIONS
  The urea breath test has shown the highest ability to detect the organism with 95-100% sensitivity in symptomatic individuals and specificity, which is comparable to other tests.
authors.affiliation: Life Science Group (LSG), Radiation and Isotope Applications Division (RIAD), PINSTECH, PAEC, Islamabad. rakhshanda.bilal@gmail.com
authors.forename: Rakhshanda
authors.initials: R
authors.lastname: Bilal
authors.forename: Bushra
authors.initials: B
authors.lastname: Khaar
authors.forename: Tabinda Zafar
authors.initials: TZ
authors.lastname: Qureshi
authors.forename: Shakeel Ahmed
authors.initials: SA
authors.lastname: Mirza
authors.forename: Tanvir
authors.initials: T
authors.lastname: Ahmad
authors.forename: Zahid
authors.initials: Z
authors.lastname: Latif
authors.forename: Imran
authors.initials: I
authors.lastname: Jaffery
authors.forename: Muhammad
authors.initials: M
authors.lastname: Omar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001944:Breath Tests; D004796:Clinical Enzyme Tests; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis*; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010154:Pakistan; D015203:Reproducibility of Results; D014508:Urea / Q000378:metabolism*; D014510:Urease / Q000378:metabolism*
chemical_list: D014508:Urea; D014510:Urease