Tips for Using COVID-19 Data

COVID-19 is caused by a novel coronavirus, SARS-CoV-2, which means it is a new virus and the public health community is learning about it in real-time. Like all diseases, we use the most current science and evidence available at any point in time to respond. One of the most important, tried-and-true tools we have to guide us in this response is epidemiological data, or data that allows us to determine how diseases like COVID-19 spread among a population of people. When dealing with COVID-19, several areas can help us know how the disease is progressing in our local community, including but not limited to:

• The number of new cases 
• The positivity rate of all who are tested
• The number of people hospitalized due to COVID-19
• The number of deaths from and related to COVID-19

Because this data is complex, it can be challenging to interpret at first glance. Our goal is to be fully transparent with the data available to us, as well as help our community understand what it means and how to use it. Below are tips for interpreting the data, as well as some important things to keep in mind.

Tips & Considerations for Interpreting JCPH’s COVID-19 Data

• When provided within the dashboard, read definitions for terms prior to assessing the data. For example, definitions for commonly used terms like “confirmed” and “probable” cases are provided. 
• Data is compiled in a variety of formats for public consumption. You can click through the tabs at the top of the dashboard to see data on cases, demographics, testing and geographical impacts.
• Data is provided as soon as it is available. This means that many of the most recently reported cases are still undergoing investigation. Due to this, data may change from day-to-day, as more information is identified. Sometimes, during the course of an investigation, cases that were thought to be residents of Jefferson County are identified as residents of another county, for example. As cases are correctly assigned to their county of residence, past numbers are updated to reflect these changes. This means that a snapshot of data reported on one day will not always contain the same counts as a snapshot on another day. 
• Some data is reported and/or available to JCPH quickly, while other data takes more time. For example, we typically receive data on new cases within 1-4 days after individuals receive a positive test for the virus (although when there are high numbers of cases this time can increase). Data on deaths, however, is not available in real-time and can take several weeks to receive as that undergoes review by CDPHE’s Vital Records Division.
• Since the beginning of the pandemic, individuals and health care providers have learned a lot about how to identify and treat this virus quicker and more effectively. We expect that is one reason why we have seen hospitalizations and deaths decrease, even when cases have increased.
• Increased testing does not cause an increase in cases. Testing simply identifies cases that already exist, so that individuals can quickly seek care and isolate themselves to protect others. Consider looking at the positivity rate of tests, or the percentage of tests that are positive for COVID-19 compared to all of the tests administered, as one indication of how present the virus is in our community. (In general, we want to keep the positivity rate below 5%). 
• Because this virus is new, there is still so much we are learning about the long-term consequences of COVID-19. For example, early research shows that survivors of COVID-19 are often experiencing serious, long-term complications from the disease, such as organ damage and neurological complications. This is very important information that is not yet reflected in public health data.