Abstract
Introduction: Since November2008, Norway's largest TB-clince (Diagnosestasjonen, Oslo University Hospital, Ullevål) has implemented Quantiferon-TB GOLD In-Tube test (QFT) as a supplement to tuberculin skin test (TST)
Aim& objectives: The aim of our study was to evaluate clinical use and consequenses of QFT results for the patient.
Methodes & design: Patients with conclusive QFT result between November 2008 and December 2009, were included in this retrospective cross-sectional study.
Results: 415 patients were included and categorized by reason for referral: Immigrants (31,1%), School children (49.6%), Immunmodulation (7.5%), TB-Contacts (10.6%), Other (1.2%). Only 14 (3,4%) patients had negative TST (Mantoux<6mm). 124 (29,9%) patients had positive Quantiferon test. While 70 (56,9%) Immigrants had positive QFT; 33 (16%) of the School Children had positive QFT result. A multivariateanalysis showed that the independent risk factors of a positive QFT test were higher age, reported TB-exposure, high-incidence TB region of birth and immigrants. QFT positivity was associated with age group>35 (OR 3.5) compared to age group<14, reported TB-exposure (OR 4.5), and high-incidence TB region of birth (OR 3.84). QFTresult was the single most important factor for determining clinical outcome: 116 patients (94.3%) of patients with positive QFT tests were selected for either preventive therapy or follow-up, versus 11 (3.8%) of patients with negative tests.
Conclusions: QFT result was the single most influencing factor on the clinicians decisionmaking. Though QFT has reduced numbers of patients given treatment and follow-up, it is important to keep in mind the limited sensitivity of QFT in certain patient groups when interpreting the QFT results.
- © 2011 ERS
