Quest Diagnostics Inc has announced that it had provided possibly erroneous results to thousands of people who had their vitamin D levels tested over the past two years.
Quest, the largest US provider of diagnostic testing, said it sent letters to doctors who might have received "questionable" test results.
Dr Wael Salameh, Quest’s medical director for endocrinology, said in an interview that the company had identified the cause of the potential errors and fixed them. He said Quest had implemented a retesting program for patients whose results were questionable.
Salameh said the questionable results emerged in roughly 10% of the tests. However, he said he expects the number of actual errors to be lower after retesting, based on the company’s internal analysis.
He said one problem was associated with a chemical used in the test, the other was improper follow-up according to standard operating procedure in some laboratories.
Salameh declined to say how many vitamin D tests had been conducted for competitive reasons, but a company spokeswoman said the impact of the retesting would not be material to its earnings.
