American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the primary benefit of using Interferon-γ release assay for tuberculosis screening?

1. It is faster than skin tests

2. It does not require a return visit

3. It is less expensive than skin tests

4. It has a lower false-positive rate

The correct answer is: It does not require a return visit

The primary benefit of using an Interferon-γ release assay (IGRA) for tuberculosis screening is that it does not require a return visit. This is a significant advantage over traditional skin tests (like the tuberculin skin test), which necessitate a follow-up visit to read the results, typically 48 to 72 hours after the initial administration. Interferon-γ release assays are blood tests that can be performed and read the same day, leading to greater convenience for both healthcare providers and patients. This feature enhances compliance since patients do not have to remember to return for a result, which can potentially improve the overall screening process and allow for timely intervention in cases of latent or active tuberculosis infection. While speed and cost are relevant factors in considering diagnostic tests, the absence of a need for a second visit significantly streamlines the process, making it easier to manage and reducing the risk of missed follow-ups. Therefore, the lack of requirement for a return visit is key in practical settings where patient adherence can impact tuberculosis control efforts.