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Test Positivity: Explained


Test positivity is the percentage of COVID testing that comes back positive. It is not the total number of positive tests. If a state or county has a high test positivity rate, it is a sign of insufficient testing in that area. To make sure there are no unknown infections that could lead to an outbreak, states and counties need to test a large enough percentage of the population. Test Positivity...

Daily New Cases: Explained


Daily new cases, also known as incidence in epidemiology, is the number of new COVID cases per day per unit of population. We use a more clear term, “daily new cases” that doesn’t require expert knowledge and calculate it per 100,000 people in states and counties. Daily new cases answers the question: “How many new infections are in my area each day?” Because we can’t test our entire population...

Recruiting A Volunteer Writer


About Covid Act Now Covid Act Now was launched on March 20. Since then, the model has reached over 10-million Americans, was cited by many counties and states in their decisions to shut down, and has been referenced by Dr. Birx in a White House press briefing. We provide data directly to 10+ governors and state epidemiologists across the country, to the Department of Defense, and to numerous...

Evolving data and assumptions: Why we are removing our old hospital projections


Covid Act Now (CAN) began as a spreadsheet model to forecast when hospitals would be overwhelmed, based on whether or not interventions (e.g. shelter-at-home) were put in place. We’ve come a long way since then. As of today, we’ll no longer be showing “Future Hospitalization Projections.” These projections were focused on hospital bed capacity, but we’ve since learned that the number...

Introducing a Critical COVID Metric: Daily New Cases Per 100K Population


Today, Covid Act Now is adding an important fifth metric to our COVID warning system: “daily new cases per 100K population” (also referred to by epidemiologists as “incidence”). The addition of this metric rounds out our warning system by incorporating a measure of how much COVID there is in each community today. Our previous metrics focused on direction of change and preparedness, but incidence...

Changes to How We Assess Contact Tracing


Based on discussions with public health experts and policy makers, we are responding to feedback on the way we assess contact tracing. We have removed the critical (red) range for contact tracing and it will no longer be possible to be marked critical (red) due to low numbers of contact tracing staff alone. While low numbers of contact tracing staff should be acknowledged, it doesn’t indicate an...

What is Incidence?


What is incidence?  Incidence is a term in epidemiology that measures confirmed new COVID cases per day. You might see this in our 5 key indicators for risk as “Daily New Cases.” We chose to use this term so that expert knowledge is not needed to understand the metric. To ensure incidence can be compared across geographies, we calculate it as a proportion of the population —...

Calculating better Infection Growth Rates (Rt) for more communities


Today we are making a change to the way we calculate Rt to better serve lower population regions and regions with lower case counts as well as to improve the timeliness of our Rt metric. We want to be more timely in letting people know when COVID is growing or shrinking in their communities, and this hopefully helps people understand how policies and actions are able to achieve different outcomes.

Launching COVID Alerts


Covid Act Now is a nonprofit organization with a mission to help save lives. To further that mission, we’re excited to launch COVID Alerts. COVID Alerts let you know when the COVID threat level — based on metrics critical to monitoring COVID, such as infection growth rate and ICU capacity — changes in your county or state. It’s easy to sign up! Just visit: Then enter...

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 Covid Act Now‘s four...

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