The North Carolina Department of Health and Human Services today announced corrections to the state’s daily and cumulative completed COVID-19 test counts after discovering a discrepancy between electronic and manual reporting of testing data that had been submitted by LabCorp. The LabCorp data error resulted in a higher count of total COVID-19 tests performed. The reporting error does NOT affect the key COVID-19 NC Dashboard trends North Carolina uses to monitor this pandemic, including the number of new positive cases and percent of tests that are positive. This error did not impact reporting of results to patients or doctors.
"Although this reporting error impacts our count of total tests completed, it does not alter our key metrics or change our understanding of COVID-19 transmission in North Carolina, which shows stabilization over the last few weeks," said NCDHHS Secretary Mandy Cohen, M.D.
The error reduces NCDHHS’s official count of cumulative tests performed from 2,044,727 to 1,823,283. It did not impact the case count total or the percent positive calculation that NCDHHS reports. Going back to the beginning of the reporting error, the data will be updated to reflect the accurate number of tests performed.
"Last week, NCDHHS informed us they had identified an inconsistency across LabCorp data submissions, which are provided to the state through both an electronic reporting system that is established through state regulations and a separate manual process as requested by NCDHHS," said Brian Caveney, Chief Medical Officer and President of LabCorp Diagnostics. "We determined that from late April until last week, Pixel by LabCorp at-home test collection kits that originated out-of-state but were processed in North Carolina were inadvertently included in the manual data submission to the state. We quickly corrected the issue and provided the updated manual reports to NCDHHS. LabCorp’s daily electronically reported data was accurate and unaffected by the error, and this issue does not affect other states or any results reported to patients or their providers."
In addition to working closely with LabCorp to correct this data reporting issue and ensure consistent data going forward, NCDHHS is taking proactive steps to increase data quality control and verification processes – including improving underlying data collection processes to reduce separate manual reporting requests and adding additional personnel to the Division of Public Health data team.
"NCDHHS is committed to data transparency and data accuracy as part of our COVID-19 response. The department is continually improving our data systems and engaging in regular quality control measures and is transparent when errors are detected," Secretary Cohen said. "We will continue to work closely with our many partners who submit data to us to help track this pandemic, including hospitals, laboratories, local health departments and many others."
As the pandemic has stretched on, NCDHHS has worked to improve data reporting systems. Currently, the state receives data on total tests and test results in two different ways. Below is background to understand why the LabCorp reporting error does not affect the key metrics of total confirmed cases or percent positive. This information has also been available on the NCDHHS COVID-19 dashboard.
How do labs provide testing data to the state?
Labs submit testing data to the state two ways: at the patient-level and in aggregate.
- Patient-level testing data (positives and negatives) is submitted either electronically through the North Carolina Electronic Disease Surveillance System (NC EDSS) or manually. Approximately 80% of total patient-level tests are now submitted electronically through NC EDSS. The other 20% that are manually submitted must then be hand-entered into NC EDSS.
- Aggregate testing data is provided by labs daily via manual communications. This is what NCDHHS uses to post the daily and cumulative report of total tests performed. NCDHHS has been working to improve data reporting processes to minimize redundancy with all labs to move to reporting exclusively through NC EDSS to improve data accuracy.
How is the rate of positive tests as a percent of total tests calculated on the COVID-19 NC Dashboard?
The percent positive rate is calculated using only patient-level electronic data in NC EDSS in order to accurately match up the total positive and negative tests run each individual day. Aggregate reports of total tests and the manually entered patient-level testing data are not included in the calculation.
So, while the reporting error affected the total tests, it did not impact the critical COVID-19 NC Dashboard metrics of total confirmed cases or the percentage of positive tests.
What is the difference between “tests” and “cases,” and how are they calculated on the COVID-19 NC Dashboard?
- Tests represent a single test performed. Multiple tests may be performed for a single patient and the test could be positive or negative results. Total tests presented on the dashboard are currently calculated using the aggregate data reports submitted via manual communications by labs.
- Cases represent individual patients testing positive for COVID-19, who may have had one or more test. Total cases presented on the dashboard are calculated using data from NC EDSS only.
So, while the reporting error affected the total tests, it did not impact a critical COVID-19 NC Dashboard metric – the total number of cases.