Table 2 Risk classification standard of POI.
Classification criteria | Risk level | ||
|---|---|---|---|
Low risk | Medium risk | High risk | |
Increase in visits (V) | 0 ≤ V < 10 million | 10 ≤ V < 30 million | V ≥ 30 million |
Increases in confirmed cases (C) | 0 ≤ C < 10 thousand | 10 ≤ C < 30 thousand | C ≥ 10 thousand |
Total increase in confirmed cases as a proportion of total increase in visits (P) | 0 ≤ P < 1‰ | 1‰ ≤ P < 2‰ | P ≥ 2‰ |
