Table 5 Hypothetical Predictive Values of Xpert detection of RIF resistance vs. DST
Prevalence of MTB culture positive | Prevalence of RIF resistance among MTB culture positive | Probability of RIF Resistance among Xpert results “MTB detected RIF Resistance detected” | Percent of Xpert results “MTB detected RIF Resistance detected” in the population | Probability of RIF Resistance among Xpert results “MTB detected, RIF Resistance not detected” |
|---|---|---|---|---|
5% | 1.0% | 48.4% | 0.09% | 0.04% |
1.5% | 58.6% | 0.11% | 0.06% | |
2.0% | 65.5% | 0.13% | 0.08% | |
10% | 91.2% | 0.47% | 0.45% | |
50% | 98.9% | 2.17% | 3.39% | |
11.8% | 1.0% | 48.4% | 0.21% | 0.05% |
1.5% | 58.6% | 0.26% | 0.07% | |
2.0% | 65.5% | 0.31% | 0.10% | |
10% | 91.2% | 1.11% | 0.51% | |
50% | 98.9% | 5.11% | 4.16% | |
20% | 1.0% | 48.4% | 0.35% | 0.05% |
1.5% | 58.6% | 0.44% | 0.07% | |
2.0% | 65.5% | 0.52% | 0.10% | |
10% | 91.2% | 1.88% | 0.54% | |
50% | 98.9% | 8.66% | 4.46% |