The COVID-19 Winter Plan set out how national restrictions would lift in England on 2 December. Decisions on which area goes into which tier are primarily based on five key epidemiological indicators as follows:
- Case detection rates in all age groups;
- Case detection rates in over 60 year olds;
- Rate at which cases are rising or falling;
- Positivity rate or the number of positive cases detected as a percentage of tests taken; and
- Pressure on the National Health Service, including current and projected occupancy.
The indicators are designed to provide a full picture of what is happening with the virus in any area so that suitable action can be taken.