Figure 1From: Screening for latent tuberculosis in Norwegian health care workers: high frequency of discordant tuberculin skin test positive and interferon-gamma release assay negative results Relationship between age, tuberculin skin test and QFT. The red triangles show the study participants with a positive QFT (n = 12). The circles show the study participants with a negative QFT (n = 355). One QFT positive was not included since no TST was performed.Back to article page