Quest Diagnostic Testing Errors ReportedJan 9, 2009 | Parker Waichman LLP Quest Diagnostics, Inc. likely released wrong information on vitamin D test results. The inaccurate test results affect possibly thousands of patients over the past two years said Reuters, which noted that Quest Diagnostics is the country’s largest diagnostic testing provider and has locations nationwide.
Newsday quoted Gary Samuels, a Quest spokesman as saying that problems in "a few of our laboratories" led to the testing errors that occurred on tests conducted from 2007 through the middle of 2008. It seems, said Samuels, that the majority of the mistakes involved exaggerating vitamin D levels in patients, according to Newsday, which explained that an error of this kind could result in patients not taking necessary vitamin D supplements. The elderly; the obese; exclusively breastfed babies; those who have limited sun exposure; people with fat malabsorption syndromes, such as cystic fibrosis; or those suffering from inflammatory bowel disease are at greatest risk for vitamin D deficiency.
Vitamin D maintains normal calcium and phosphorus blood levels; aids in the absorption of calcium, which helps develop and maintain strong bones; and protects against osteoporosis, high blood pressure, cancer, and some autoimmune diseases, explains the Mayo Clinic. Vitamin D deficiency could lead to rickets in children, which can cause skeletal deformities; in adults, vitamin D deficiency can cause osteomalacia, which results in muscular weakness and weak bones, says the Mayo Clinic.
According to Quest’s medical director for endocrinology, Dr. Wael Salameh, the mistakes originated with the test's “reagents and calibrators,” which involve a chemical used in the testing; "issues with some sites not following proper operating procedure," were also to blame, Salameh said, reported WebMD. Quest notified physicians by letter late last year and offered free retesting, according to Samuels, said Newsday. Samuels reported that Quest has fixed the cause of the errors and that about 10 percent of the tests are likely questionable, said Reuters. Salameh would not provide information on the number of vitamin D tests conducted citing competitive reasons for its refusal to release the data, Reuters noted.
Although Quest Diagnostics refused to provide figures on the number of vitamin D tests it conducts, Newsday said that vitamin D testing has been on the rise in recent years following studies which have linked lower vitamin D levels with heart attacks, bone weakness, and other conditions. USA Today reported that lower vitamin D levels might also be linked to certain cancers, diabetes, and immune system disorders. Richard Reitz, a Quest medical director told USA Today last year that vitamin D testing rose by approximately 80 percent in the one-year period from May 2007 to May 2008.
It seems that last June, doctors began calling the lab and questioning test results, said USA Today; it was at that time that Quest opened its investigation of the problem. Newsday also reported that the editor of Dark Report, Robert Michel, the paper that broke the story, said, "The question most lab professionals would ask is why would it take 18 months to recognize the problems and begin to offer retests." Michel pointed out that the Quest lab test recall is the largest such recall of its kind that he is aware of since he entered the field nearly 20 years ago.