Table 4 Risk scores used to determine classification of countries according to wild and cVDPV risk and associated sensitivity, specificity and historical probability of an outbreak
Classification | Low | Medium | Medium high | High |
|---|---|---|---|---|
Wild-type assessment | ||||
Score from risk factors | 0–2 | 3 | 4–5 | 6–8 |
% of observations associated with an outbreak (95% CI) | 0.8 (0.4, 1.3) | 5.6 (3.1, 8.2) | 18.5 (14.3, 23.9) | 35.2 (24.2, 46.4) |
Sensitivity | 100.0% | 89.9% | 69.7% | 24.2% |
Specificity | 0.0% | 67.9% | 86.5% | 97.5% |
cVDPV-type assessment | ||||
Score from risk factors | 0–3 | 4–5 | 6–7 | 8–9 |
% of observations associated with an outbreak (95% CI) | 0.3 (0.1, 0.6) | 2.5 (1.2, 4.1) | 12.5 (4.1, 22.2) | 34.3 (18.2, 51.6) |
Sensitivity | 100.0% | 88.2% | 67.6% | 38.2% |
Specificity | 0.0% | 73.1% | 93.4% | 99.0% |