Table 6 Confidence limits (95%) for PPV and NPV values for simulations presented in Fig. 8. Prevalence threshold 30.0% two years after cessation of MDA. Data from 100 village simulations with 500 people per village
Raw data from 300 simulations | Bounce back | Transmission interruption | Totals |
|---|---|---|---|
Test positive | 1 | 89 | 90 |
Test negative | 7 | 3 | 10 |
Totals | 8 | 92 | 100 |
| Â | Â | 95% Confidence limits | |
| Â | Estimated value | Lower limit | Upper limit |
Prevalence of interruption | 0.920 | 0.844 | 0.962 |
Sensitivity | 0.967 | 0.901 | 0.991 |
Specificity | 0.875 | 0.447 | 0.993 |
Probability of simulation being either transmission interruption or bounce back | |||
 Interruption | 0.9 | 0.819 | 0.948 |
 Bounce back | 0.1 | 0.052 | 0.180 |
For predicted elimination - probability of being true or false | |||
 True positive (PPV) | 0.989 | 0.930 | 0.999 |
 False positive | 0.011 | 0.001 | 0.069 |
For predicted bounce back - probability of true or false | |||
 True negative (NPV) | 0.700 | 0.354 | 0.919 |
 False negative | 0.300 | 0.081 | 0.646 |
Likelihood ratios | |||
 Positive (C) | 7.739 | 1.237 | 48.42 |
 Negative (C) | 0.037 | 0.012 | 0.117 |
 Positive (W) | 89.000 | 12.673 | 625.03 |
 Negative (W) | 0.428 | 0.153 | 1.201 |