Targets and horizons

There is no obligation to submit for all suggested targets or horizons, and it is up to you to decide what you are comfortable doing with your model.

Please take care when submitting to be clear which target and horizon you are using: use this page and the formatting guide.

Targets

Targets

We are currently focused on three forecast targets:

• Weekly new COVID-19 cases
• Weekly new COVID-19 deaths

You can submit projections for only cases or deaths, or multiple targets.

We only use incident counts: the count of new cases or deaths per week. We do not use cumulative (running total) forecasts. This varies from other hubs.

Horizon and frequency

Horizon

For the scenario hub, we focus on horizons of between 1 and 26 weeks ahead.

Date format

Horizons should use the Epidemiological Week (EW) format, defined by the US CDC. Each week starts on Sunday and ends on Saturday. For example:

• A 1 week ahead case projection submitted on Monday 4th January 2021 should cover the seven days including Sunday 3rd January to Saturday 9th January. In this example, the forecast file would include:
  • forecast_date = "2021-01-04"
  • target_variable = "inc case"
  • horizon = 1 wk
  • target_end_date = "2021-01-09"
• A 4 week ahead case projection submitted on Monday 4th January would include the period Sunday 24th January to Saturday 30th January 2021. In this example:
  • forecast_date = "2021-01-04"
  • target = "inc case"
  • horizon = 4 wk
  • target_end_date = "2021-01-30"

Note that weeks start on a Sunday, but we require submission by the Monday evening of that week.

Location

You can submit for a single country, or any combination of the target countries (EU, EFTA and the UK). We use ISO-2 codes to identify countries.

Currently we do not accept sub-national projections. Sub-national country datasets can be incompatible with each over and over time, making comparisons between projections unclear.