Abstract 04

Over Fifteen Years Experience in Workplace Drug Testing - What Is Old, What Is New and What Have We Learned: the Laboratory's Perspective

Michael A. Peat

Executive Vice President, Toxicology, LabOne Inc., Overland Park, Kansas, USA.

Fifteen years ago very few employers had workplace drug testing programs. At that time workplace drug testing was essentially limited to the U.S. Military and a few major corporations. Over the remainder of the 1980s more and more employers introduced drug testing programs and today it is unusual for an employer not to have such a program. This rapid growth was fueled by a number of watershed events, among the most prominent were:

  • several major accidents in the transportation industry that were associated with drug use.
  • President Reagan's Executive Order requiring drug testing of federal employees
  • development and implementation of the U.S. Department of Transportation's (DOT)
  • Regulations covering drug testing of workers in the transportation industries.

Of equal importance to the drug testing laboratories was the development and introduction of Department of Health and Human Services Certification ('NIDA Guidelines'). Laboratories wishing to test specimens from federal employees and those covered by the DOT Regulations have to be certified by these Guidelines. They mandate requirements for specimen security and chain of custody, quality control and data review, the use of a FDA approved immunoassay and gas chromatography-mass spectrometry (GCMS) for testing specimens, the testing of specimens for a limited number of drugs of abuse and the reporting of results to Medical Review Officers. These requirements have now become the 'standard of care' for workplace drug testing in the United States and are even followed by companies and organizations not covered by federal regulation. Indeed many states have incorporated them into their regulations. They have had a significant positive impact on the quality of laboratory testing. Some of the positive benefits are as follows:

  • consistency in the approach used to test workplace specimens.
  • use of quality control procedures by toxicology laboratories.
  • introduction of improved immunoassays for initial testing.
  • improved technology for GCMS procedures.
  • greater confidence in the laboratory testing data.

Fifteen years ago the quality of drug testing laboratories was extremely variable. A number of laboratories used immunoassays for screening followed by GCMS for confirmation. However, there were others that used thin layer chromatography for screening specimens with no confirmations or simply performed an immunoassay screen. Requiring specimens to be screened by a FDA approved assay and confirmed by GCMS has been one reason for the much greater confidence in the testing results.

The dramatic increase in the number of specimens to be tested has led to several beneficial technology developments for the laboratories. One of these has been the introduction of 'newer' immunoassays which have different characteristics than the more traditional ones (for example EMIT and RIA). Although most drug testing laboratories in the U.S. still use the EMIT assays, an increasing number are using KIMS technology (Roche Diagnostic Systems) and a few the CEDIA assays (BMC). KIMS technology, which is based on microparticles, has several advantages, including being more resistant to adulterants and having much greater calibration curve stability, over the enzyme based assays. Not only has laboratory based immunoassay testing improved, but there are now reliable on-site technologies available, for example the TestCup (Roche Diagnostic Systems). These, together with the testing of specimens other than urine, present new challenges to the regulators - are they suitable for workplace drug testing?

There has also been significant developments in GCMS hardware and software over the past 15 years. Today technology is such that drugs can be confirmed in very short run times and data reviewed by automated software using the Finnigan Toxlab system. These developments have considerably shortened the turn around times for positives.

In the U.S. these changes have all taken place within the confines of a very competitive market place where employers now expect negative results within 24 hours of collection and positives within a further 24 hours. Pricing pressures on the laboratories have also increased dramatically over the last 15 years, to the point where small laboratories can no longer compete effectively. This has led to the advent of large production drug testing laboratories, which are certified by HHS and are testing several thousand specimens per day. LabOne is one such laboratory. Processing these numbers of specimens has led to new challenges for analytical toxicologists - they now need to be familiar with manufacturing techniques, such as statistical process control, and with the technology needed for information transfer. These are rapidly becoming the new challenges facing the drug testing laboratories within the U.S.

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