Acceptance of interferon-gamma release assay by a high-risk urban cohort

BACKGROUND: QuantiFERON ® -TB Gold (QFT-G), an interferon-gamma release assay, is approved for the diagnosis of latent tuberculosis infection (LTBI). It is unknown if patients at high risk for LTBI will more readily accept LTBI treatment based on tuberculosis skin testing (TST) or QFT-G. METHODS: Prospectively enrolled participants were i nterviewed, were read an informational paragraph on QFT-G, completed a questionnaire and were tested with QFT-G. RESULTS: A total of 230 consecutive participants with a history of hepatitis C virus infection and active or past illicit drug use were enrolled and underwent QFT-G testing: 77% had recent TST, 82% were human immuno- de ciency virus co-infected, 87% had a history of injec- tion drug use, and 52% a history of homelessness. Of the 230 participants, 148 (64%) stated a preference for TST compared to QFT-G. The majority would take treatment based on either test (68%). A minority of pa- tients (20%) stated a willingness to take LTBI treatment based on TST alone. Black race was associated with a willingness to take treatment based on TST (OR 2.72, 95%CI 1.05-7.10). CONCLUSIONS: Patients at high risk for LTBI were found to prefer TST to QFT-G. Most would accept treatment based on either test, and a subset stated unwillingness to take treatment based on QFT-G results. Outreach and education should accompany QFT-G roll-out in high-risk urban populations.