Quest’s Deficiencies Trigger QA/QC Questions

Problems in test accuracy should be studied and relevant lessons shared with lab industry

CEO SUMMARY: Experts in laboratory QA/QC and proficiency testing (PT) are following the news that Quest Diagnostics admitted to an 18-month problem with lab test accuracy in its home brew Vitamin 25(OH) D assay. It is recognized as a major failure in the existing system of laboratory licensure, accreditation, and proficiency testing. However, to improve current lab quality standards, more needs to be known about how quality systems failed at Quest Diagnostics.

PATHOLOGISTS ACTIVE in laboratory quality assurance/quality control (QA/QC) organizations are beginning to react to the national headlines that Quest Diagnostics Incorporated was reporting inaccurate Vitamin 25(OH) D test results.

Two facts catch their attention. First, Quest Diagnostics has acknowledged that tens of thousands of patients and their physicians were given inaccurate results for Vitamin 25(OH) D. Based on what is known about Quest’s Vitamin D testing program, THE DARK REPORT estimates that between 350,000 and 490,000 patients are involved in Quest’s voluntary notification and retest program.

Second, Quest has publicly admitted that its Vitamin D testing program produced inaccurate results over an 18-month period, from early 2007 through mid-2008. It has told reporters that about 7% of the total Vitamin 5(OH) D tests performed during this time were inaccurate.

In terms of the number of patients affected, a laboratory quality management failure on this scale is unprecedented in the profession of laboratory medicine. Further, Quest Diagnostics is a lab company that builds its public image and branding around the twin themes of reliability and high quality, along with patient/physician trust in its accuracy. It has consistently touted its commitment to Six Sigma quality management methods as setting it apart from competing labs. These are additional reasons why deficiencies in its testing stunned the laboratory profession at large.

Important Questions

“From the laboratory QA/QC perspective, these public disclosures about a major failure in laboratory testing accuracy raise many important questions,” stated medical microbiologist Michael A. Noble, M.D., FRCPC, Chair, Program Office for Lab Quality Management, University of British Columbia in Vancouver, Canada.

“In most North American and international laboratory quality commissions, agencies, and committees, Quest’s problems with its testing program will be discussed and studied,” predicted Noble. “After all, Quest Diagnostics participates in many of these quality management programs itself and was generally viewed as being a leader in laboratory test quality and integrity. So it becomes a relevant goal for professionals in laboratory quality to do—if you will—their own root cause analysis. Were quality guidelines inadequate to prevent this situation? Alternatively, were there organizational dynamics within Quest Diagnostics that overrode the institutional quality management requirements?”

Noble has an interesting perspective on laboratory quality management. He operates an ISO 9001:2000 certified proficiency testing program for Canadian laboratories. For laboratory quality managers, he provides international proficiency testing training, as well as a university certification course. He is a member of Technical Committee 212 for the International Standards Organization (ISO). This body wrote the standards for ISO 15189: Medical Laboratories, as well as other ISO standards for in vitro diagnostics (IVD). He is active in laboratory quality programs supported by such agencies as the Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO).

“Many of us with a professional focus on laboratory quality management were disappointed to learn that Quest Diagnostics had admitted to these serious problems,” observed Noble. “Besides the obvious consequences to Quest and its reputation with physicians and patients, this major failure in lab test integrity has implications for the design and adherence of existing laboratory quality systems, licensing, and proficiency.

Quality Oversight In Labs

“Important questions must be asked, both of Quest Diagnostics and those governing agencies delegated with quality oversight in laboratory operations and laboratory competence,” added Noble. “Let me run through the key questions.

“Where were all the watchdogs tasked with insuring quality and integrity in clinical laboratories in the United States?” he asked. “There are multiple levels of authority that have a role in monitoring lab quality. These include CMS and the Medicare program, CLIA, CAP accreditation, and proficiency testing (PT).

“One starting point is how Quest Diagnostics validated its laboratory-developed test (LDT) for the Vitamin 25(OH) D assay,” continued Noble. “There are clear, detailed standards. If Quest was following these standards, then why did its assay fail when introduced as a regular clinical service? Why did it take so long to respond to these testing concerns?

Lab Failures Affect Patients

“Most of the national news reports included recognition that these failures to provide accurate, reliable test results to physicians and patients had the potential to negatively affect patient care,” declared Noble. “To its credit, the New York Times reporter did interview physicians on this point. The media plays an important role in promoting quality practices when it shines the light on events that can erode public confidence.

“Proficiency testing (PT) is my primary professional interest,” said Noble. “PT testing is a major safeguard and guidepost to help a laboratory have confidence in the quality and integrity of its laboratory test accuracy. Once Quest Diagnostic introduced its home brew Vitamin D assay, how and why did its proficiency testing program fail to detect the problems in a timely fashion?

“Particularly troubling to lab quality assurance experts is the disclosure by Quest Diagnostics that its problems went on for at least 18 months,” he stated. “Did their PT program fail to detect errors in Vitamin D challenges over that whole extended period? If so, we need to fix any weaknesses in existing PT standards.

“Alternatively, was the PT team at Quest Diagnostics swamped and overwhelmed by any or all of these factors: size of the Vitamin D testing program, its multiple testing sites, and the ever-increasing number of samples coming in each night?” asked Noble. “Of course, there could be other reasons why proficiency testing did not change the situation. For example, did the PT team hide their findings or remain silent because of fear about the consequences of going on the record that a sizeable number of lab test results were inaccurate? Remember, proficiency testing is supposed to be the front line of quality for every accredited and licensed laboratory.

Accreditation And Inspection

“Another quality management aspect that should be scrutinized is the intersite comparison, accreditation, and inspection process,” added Noble. “Quest says it performed these Vitamin D tests at seven laboratory sites. It also said that four of these sites produced unreliable test results—at the surprising rate of 7% inaccuracy—over a period that extended to 18 months!

“Nearly all these seven laboratory sites were likely to have had their CAP (College of American Pathologists) accreditation inspections during that 18-month period,” he said. “What happened during these inspections? Did the inspectors execute their responsibilities properly? On the other hand, what did the laboratory staff know about issues in the Vitamin D testing program? Was that knowledge communicated to the inspection team while they were on site?

“All laboratory professionals recognize that laboratory licensing, accreditation, and proficiency testing requirements are not perfect solutions to guarantee lab test accuracy and reliability,” commented Noble. “However, it is the starting point to protect patients and provide quality lab test results to clinicians.

“Thus, when a significant quality failure like this surfaces, our profession needs to understand what worked and what didn’t,” he explained. “This is the scientific process. I would like to call upon Quest Diagnostics to share its analyses of its problems with this Vitamin D testing program with the laboratory testing profession. What are the lessons it has learned that need to be evaluated and incorporated by other laboratories?

“We know that every laboratory has errors and deficiencies. That is the underscored reality that necessitates the cycle of continual improvement processes,” added Noble. “What is important is how the laboratory responds to those mistakes. Quest Diagnostics seems to have fulfilled its requirements to self-assess, correct its internal problems, notify physicians and patients who may have received inaccurate Vitamin 25(OH) D results, and retest those patients. It would be beneficial to the entire lab profession for Quest Diagnostics to share lessons. That would allow us in the quality management community to revise and improve guidelines and requirements in ways that advance lab quality and boost lab test integrity.”

Noble also believes that the publicity about Quest Diagnostics’ acknowledgement of inaccurate Vitamin D results may have another consequence for the lab industry. “In the United States, requirements for CLIA, Medicare accreditation, and state laws have already created plenty of fear in labs that they might lose their operating status were they to be truly forthcoming in acknowledging all the deficiencies that often occur in daily operations.

Gaming Quality Oversight

“Such a motivation already exists to game PT and accreditation inspections,” explained Noble. “Now, recent widespread publicity about Quest’s problems with inaccurate Vitamin D results adds to that motivation. Having seen the publicity blitz surrounding Quest’s acknowledgement of its deficiencies, one consequence can be to make a laboratory more reluctant to self-disclose problems as it follows PT, QA/QC, and other quality requirements.”

To date, no other pathologist or official involved in laboratory licensing, accreditation, and proficiency testing has made a public statement about this matter. Thus, it remains unknown as to what type of regulatory response may yet result.

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