Model Changes: Adding a Fourth Color

Previously, our model depicted risk in three colors: red, yellow, and green. We have now added a fourth color: orange.

Using four colors allows the Covid Act Now threat scores to be more nuanced, reflecting the more messy, complicated reality of COVID in America. The addition of a fourth color (orange) allows red to be reserved for truly critical situations.

Here are the four colors and what they mean:

  • Red: Active or imminent outbreak. Red is reserved for the most severe situations in which data indicate that COVID is spreading rapidly and might foreshadow a new wave of infection. 
  • Orange: Risk of second spike or major gap in at least one of the metrics. A state categorized as orange and “at risk” can quickly devolve to an active or imminent outbreak, barring intervention.
  • Yellow: Does not meet standards for containment. This means that the disease is still spreading, but in a slow and controlled manner that is unlikely to overwhelm the healthcare system.
  • Green: On track for containment. This means that the rate of disease growth is negative, government testing and tracing efforts are robust, and that overall COVID is in retreat.

To make room for the fourth color, we’ve shifted the thresholds for some of the metrics. Here are the new thresholds for each metric.

Infection Growth Rate:

Red: >1.4

Orange: 1.1 – 1.4

Yellow: 0.9 – 1.1

Green: < 0.9

Test Positivity Rate:

Red: >20%

Orange: 10% – 20%

Yellow: 3% – 10%

Green: < 3%

ICU Headroom:

Red: >70%

Orange: 60% – 70% 

Yellow: 50% – 60%

Green: < 50%

Percent of Necessary Contacts Tracers Hired:

Orange: <20%

Yellow: 20% – 90% 

Green: >90%

For more detailed information on each metric, why we chose it, and why we chose the cutoffs, check out this previous post.

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