20,000 Hours of Data Entry: Why We Didn’t Automate Our Data Collection
Looking back on a year of collecting COVID-19 data, here’s a summary of the tools we automated to make our data entry smoother and why we ultimately relied on manual data collection.
A Wrap-Up: The Five Major Metrics of COVID-19 Data
As The COVID Tracking Project comes to a close, here’s a summary of how states reported data on the five major COVID-19 metrics we tracked—tests, cases, deaths, hospitalizations, and recoveries—and how reporting complexities shaped the data.
How Probable Cases Changed Through the COVID-19 Pandemic
When analyzing COVID-19 data, confirmed case counts are obvious to study. But don’t overlook probable cases—and the varying, evolving ways that states have defined them.
Releasing Our State COVID-19 Data Log
From July 2020 to March 2021, The COVID Tracking Project compiled a detailed set of structured COVID-19 data notes, both on changes states made to the data and changes we made to the data we captured from states. Today, we’re releasing those notes.
How We Entered COVID-19 Testing and Outcomes Data Every Day for a Year
We set up a set of roles and a shift system to carefully gather and inspect the data we published.
Federal COVID-19 Testing Data Is Getting Better
The federal government improved its state and county-level COVID-19 PCR testing data since we analyzed it in February. Here’s an update on those changes and what we hope to see next for the data.
Inconsistent Reporting Practices Hampered Our Ability to Analyze COVID-19 Data. Here Are Three Common Problems We Identified.
With little consistency in how states defined, published, and presented COVID-19 data, it is difficult to compare situations across states.
A New Surge Has Arrived in Michigan, but We Don’t Know What It Will Look Like
According to federal data, COVID-19 cases and hospitalizations have reversed their decline in Michigan, marking a new surge concentrated in and around Detroit, but affecting regions statewide.
Giving Thanks and Looking Ahead: Our Data Collection Work Is Done
While our work to compile COVID-19 data has concluded, we will continue to share research, analysis, and documentation in the months ahead. We are enormously grateful to the hundreds of volunteers who made this work possible.
Releasing our Annotations on COVID-19 State Data Definitions
As part of our wind-down process, we’re publicly sharing our structured metadata on state COVID-19 data definitions.
Federal COVID Data 101: Working with Testing Data
At least three different federal agencies share testing data for SARS-CoV-2 in at least four different places. Here’s a little about where that data comes from, what each dataset has to offer, and how you can use the datasets best in light of their large differences from state-provided data.
Where to Find Simple COVID-19 Data for the US
As The COVID Tracking Project approaches its final day of data compilation on March 7, 2021, we are recommending a selection of federal data sources to people who want a quick and easy way to keep an eye on the pandemic.
How Day-of-Week Effects Impact COVID-19 Data
An understanding of state reporting schedules and day-of-week effects can help explain the reasons that numbers fluctuate from day to day, and what those changes mean.
Federal Testing Data’s Last Mile
Federal testing data is already more standardized and more detailed than the data we compile from states can ever be. But in some jurisdictions, state-provided data still provides a more comprehensive picture of testing volume. The federal government should address lingering quality problems so its data can become the national standard.
Silent Data Mismatches Are Compromising Key COVID-19 Indicators
Although we’d prefer to have precise, real-time, comprehensive COVID-19 data for every US state and territory, the reality is that every metric that each jurisdiction publishes comes with quirks of timing and content that can make precise calculations impossible.
All Eyes on Hospitalizations: This Week in COVID-19 Data, Dec 30
Holiday reporting has garbled most metrics. Going by current COVID-19 hospitalizations, outbreaks in the Midwest are still easing, but every other region is in trouble.
How We Source Our Data and Why It Matters
States provide COVID-19 data in a variety of sources and formats. To ensure our data is as accurate and consistent as possible, we spend a lot of time looking at these sources to make sure that we’re capturing the most data possible for each state, while maintaining high standards of data quality and integrity. Today, we’re publicly releasing a detailed set of notes on the sources of all our data points.
Test Types 101: The Pros and Cons of Different Approaches
Once limited to molecular tests, the United States now has other testing methods available. Their efficacy depends on multiple factors, including how far the person tested is in their infection and how high the test positivity is where they live.
Daily COVID-19 Data Is About to Get Weird
The upcoming holiday means that many COVID-19 metrics are going to drop—and then rise—in ways that may trip up unsuspecting observers. Here’s what to watch out for.
What We Know About Covid Testing Sensitivity
To successfully manage the pandemic, we need tools for both surveillance and diagnosis, in the form of antigen tests and PCR tests.
Ultralight Recommendations for a National Pandemic Dashboard
The announcement of a forthcoming national pandemic dashboard is heartening news for COVID-19 data folks all over the country. We have a few modest suggestions for the team that will undertake this work.
Good News about Florida’s Testing Data
Florida is now publishing a full time series of test encounters, so we are picking up this metric in our API and on our website.
Cases Matter
As COVID-19 cases rise across the United States, claims are circulating that case increases are (mostly or entirely) due to expanded testing, and do not indicate a spike in infections. The data does not support this conclusion.
The State of State Antigen Test Reporting
Antigen tests are becoming a major tool for rapid COVID-19 testing. But if states don’t report results clearly, we won’t know the true impact of these tests.
Test Positivity in the US Is a Mess
Interpreted correctly, test positivity can tell us so much that we need to know about COVID-19 outbreaks and testing in the United States. But we don’t publish test positivity calculations for US states and territories. Here’s why.
Test Positivity: So Valuable, So Easy to Misinterpret
Test positivity is extremely useful, but it has also become one of the most commonly misunderstood metrics for monitoring the COVID-19 pandemic. Here, we take a step back and look at what it really means.
Holiday Reporting Lags Interrupt Positive Trends: This Week in COVID-19 Data, Sep 17
Though cases are rising in parts of the Midwest, hospitalizations in the West and South continued trending downward. The Labor Day holiday impacted data reporting lag times both this week and last, obscuring what had been positive trends in September.
Testing In Limbo, Hospitalizations and Deaths Still Dropping: This Week in COVID-19 Data, Sep 10
A long holiday weekend makes ambiguous testing data even harder to understand, but hospitalizations are dropping, which is good.
Cases Stop Dropping and the Midwest Heats Up: This Week in COVID-19 Data, Sep 3
After five straight weeks of sharp declines in new cases of COVID-19 in the United States, we’ve leveled off again. Reported tests are up about 5 percent, but are actually dropping in the Midwest, where three states—Iowa, North Dakota, and South Dakota—are driving an uptick in new cases. This week we also launched a new dataset that looks closely at the toll of COVID-19 in nursing homes and other long-term care facilities.
Something Is Wrong with Testing Data in the Great State of Texas
According to the official state numbers, COVID-19 testing has dropped dramatically in August. However, county-level statistics show the opposite story. What’s going on?
Counting COVID-19 Tests: How States Do It, How We Do It, and What’s Changing
Many states have moved toward greater transparency about their test data reporting methods, and we’re making changes to better represent what they publish. We’re also introducing a “new” way some states are counting tests—one we think all states and territories would be wise to embrace.
Tests, Cases, and Hospitalizations Keep Dropping: This Week in COVID-19 Data, Aug 13
Testing continues to fall, especially in the South, one of the areas where the country needs it the most. Cases, too, are falling, which remains hard to interpret, given the testing decline—but fewer people are now in the hospital with COVID-19 than last week. This is the second week in a row that hospitalizations seem to have dropped, which suggests that infections may be declining independently of testing reductions.
Florida’s Per-Capita COVID-19 Cases Just Surpassed New York’s, but Are the Two Outbreaks Comparable? Yes and No.
Florida has reported over 461,000 total COVID-19 cases, surpassing New York for the highest per-capita caseload in the United States—but a simple comparison doesn’t represent the critical differences in the data we have for the two outbreaks.
Record New Cases, Surging Hospitalizations, Rising Deaths: This Week in COVID-19 Data, July 9
The South continues to be the epicenter of surges in both cases and hospitalizations. In Arizona, Florida, South Carolina, and Texas, COVID-19 deaths have begun to climb following jumps in new cases. And for the first time since April, deaths are rising nationally.
This Week in COVID-19 Data, July 2: Across the US, Outbreaks Are Catching Fire
The US has broken its record for new COVID-19 cases three times in the last week. Thirteen states broke their new-case records since Sunday. In the states with the worst outbreaks, hospitalizations and deaths are rising.
Better COVID-19 Data Is Coming By August 1—But Will the Public See It?
Starting in August, new federal rules will require testing labs to report better data on the spread of COVID-19 in the United States. What happens to this new information is up to state and local officials. Journalists, open-data advocates, and members of the public can help us hold governments accountable for collecting and publishing this urgently needed data.
The Other COVID-19 Metric We Should Be Using
As exposure risk increases, so does the need for more testing. The more we test, the more cases we can identify—which is a good thing. But are we looking at the right metrics to know if we are performing enough tests?
Weekly COVID-19 Data Update, June 25: The US Pandemic Is Surging in the South and West
The United States hit a record high for new COVID-19 cases this week. In many areas with rising case counts, testing isn’t keeping up. Meanwhile, hospitalizations in regions with big outbreaks are increasing.
It's Not Just Testing
As case counts surge, we look at regional and state-level numbers to find out which recent jumps in COVID-19 case counts are likely to be explained by increased testing, and which are not. For the states with the worst recent numbers, the news is not good.
Weekly COVID-19 Data Update, June 18: The Regional Gap Widens
As cases and hospitalizations continue to drop in the early Northeast epicenters, they are rising—in some areas quite sharply—in the South and West. We look at the numbers and at the relationship between an increase in tests and a rise in case counts.
What Is a Probable Case of COVID-19?
Probable cases of COVID-19 make up only a small fraction of currently reported cases, but the CDC wants states to do a better job reporting them. So what are they and why do they matter? We took a closer look to help reporters and members of the public better understand this complex COVID-19 metric.
Weekly COVID-19 Data Update, June 11: Early Data from May Transmission
The news this week is mixed and highly regional. In the early US epicenter of the outbreak, cases continue to drop. In the southern and western United States, cases are on the rise, as are COVID-19 hospitalizations. And as always, the lag makes the data difficult to put into context.
Tracking the States and the CDC
For months, we've worked to patch together inconsistent state-reported data into a national set of numbers for COVID-19 case, death, and testing in the US. The CDC has now published a COVID Data Tracker, but their data only partially matches the numbers we get from the state public health authorities. So we took a closer look.
Position Statement on Antibody Data Reporting
As antibody tests become more widely available across the United States, we call on all states and territories to preserve the integrity and usefulness of their COVID-19 testing data by maintaining separate viral testing and antibody testing counts.