University of Kentucky says scientists found false positive COVID-19 tests
Patients who received incorrect COVID-19 results from UK HealthCare have been notified after problems with about 26 tests were discovered, the system disclosed Thursday.
The false positives were caused by a software flaw in one of four testing platforms — which are essentially machines used to interpret test results. According to UK HealthCare, lab scientists were inspecting data from the Massachusetts-based Thermo Fisher testing platform when they discovered there were discrepancies between the raw data and the “software interpretation,” according to Thursday’s announcement.
The lab retested the “suspect samples” on another testing platform, and confirmed false positives, according to UK HealthCare. UK scientists have since reviewed all the COVID-19 positive tests on the Thermo Fisher testing platform. Results with a discrepancy were retested on another platform.
The retests confirmed 26 false positives and no false negatives, UK HealthCare said.
A testing platform is a machine that can analyze tests and give lab workers raw data that they can interpret as either positive or negative results, said Dr. Mark Newman, UK’s executive vice president for Health Affairs. Most labs have more than one testing platform for a particular disease and UK is now re-testing all of its positive COVID-19 results on other platforms to confirm them, he said.
“For anyone tested at UK HealthCare, it is important to know that the vast majority of results have not changed,” Newman said in a statement. “Since these very astute employees discovered this issue, we have taken extensive measures to validate each test in question and worked diligently to contact all parties — the vendor, the FDA — and most importantly, our patients and providers.”
Newman said the clinical lab has done more than 30,000 tests since March, and only a “very small percentage” of tests have been affected by the software issue. The 26 false positives would make up less than 0.1 percent of those tests.
Part of the reason that the hospital system went public with the false positive results is so that patients, who were not contacted, can be confident in their test results, Newman said.
It’s possible that other labs with the Thermo Fisher testing platform could be running into similar problems, Newman said.
“That’s part of the reason to make it public, it’s so that we can improve the quality across the board, not just what we’ve been able to identify,” Newman said.
UK is also working with local health departments and the Kentucky Department of Public Health to correct data.
This story was originally published July 23, 2020 at 9:09 AM.