Table 2.
Explanatory variables used in the risk score to assess poliomyelitis outbreak risk, based on a regression analysis of data from 2003 to 2016
| Variable | Factor | p-value | Risk estimate (95% CI) | Risk score |
|---|---|---|---|---|
| Population immunity | ||||
| Under-immunised | 0–20% of non-polio AFP reporting 0–2 OPV doses | baseline | 0 | |
| >20% of non-polio AFP reporting 0–2 OPV doses | 0.180 | 1.48 (0.84, 2.61) | 1 | |
| Zero dose | 0–20% of non-polio AFP reporting 0 OPV doses | baseline | 0 | |
| >20% of non-polio AFP reporting 0 OPV doses | 0.427 | 0.4 (0.04, 3.82) | 1 | |
| Routine immunisation | 80–100% of children under 2 with 3 DPT doses | baseline | 0 | |
| <80% of children under 2 with 3 DPT doses | 0.023 | 2.64 (1.57, 4.45) | 1 | |
| Exposure to poliomyelitis | ||||
| Bordering countries with wild poliomyelitis in last 6 months | No | baseline | 0 | |
| Yes | <0.001 | 4.77 (2.31, 9.88) | 1 | |
| Migration and wild exposure | Low | baseline | 0 | |
| Medium | 0.060 | 1.77 (0.98, 3.2) | 1 | |
| High | <0.001 | 5.58 (2.93, 10.65) | 1 | |
| Migration and wild poliomyelitis exposure - expert opinion | Limited evidence of wild poliomyelitis exposure | baseline | 0 | |
| Evidence of wild poliomyelitis exposure | not tested | not tested | 1 | |
| Susceptibility | ||||
| Population displacement | 0–10% of population displaced | baseline | 0 | |
| >10% of population displaced | 0.116 | 1.62 (0.89, 2.94) | 1 | |
| Diarrhoea-associated mortality | 0–199 deaths per 100,000 per year in children <5 years | baseline | 0 | |
| >200 deaths per 100,000 per year in children <5 years | 0.001 | 1.96 (1.1, 3.52) | 1 | |
| Previous importations | No wild poliomyelitis importations in previous 4 years | baseline | 0 | |
| Wild poliomyelitis importations in previous 4 years | <0.001 | 2.75 (1.52, 4.97) | 1 | |
| Humanitarian emergencies - expert opinion | None reported | baseline | 0 | |
| Country of concern | not tested | not tested | 1 | |