Skip to main content
Figure 4 | BMC Infectious Diseases

Figure 4

From: Choosing algorithms for TB screening: a modelling study to compare yield, predictive value and diagnostic burden

Figure 4

Number needed to screen to find one true case of active TB and positive predictive value of each algorithm at different levels of TB prevalence. Panel A: Number needed to screen (NNS) to find one true positive (TP) case; Panel B: Positive predictive value (PPV). CXR = chest X-ray for screening; SSM = sputum smear microscopy; XP = Xpert MTB/RIF; 1 = first screen; 2 = second screen if first is positive.

Back to article page