Work-related Alcohol and Drug use - A National Forum.
30th June 2006.
The second session of day 2 of the forum tackled the controversial area of "Drug Testing (vs Fitness For Work)"
It began with Dr John Lewis, Head of the Toxicology Unit of Pacific Laboratory Medicine Services speaking on "Urine drug testing in the workplace - The message in the bottle". Dr Lewis, whose experience in toxicology began with greyhound testing, observed that Australians are world leaders, having: in 1900, the worlds highest per capita laudanum/patent opiate consumption; in the 1950s the highest per capita (legal) heroin consumption; in the 1960s highest per capita compound analgesic consumption (and Crown Princes of analgesic nephropathy); and in the noughties, reportedly the worlds highest per capita MDMA consumption.
Drug testing is old, having started with horse racing in the 1930s and having been used regularly in humans first by Vincent Dole in the pioneering methadone programmes in the 1960s, then in the Vietnam war and in the 1970s in the Olympics. However, workplace drug testing is recent, starting with Ronald Reagan's edict in the 1980s "You work for me, no drugs" - NIDA and SAMHSA (Substance Abuse and Mental Health Services Administration) enacted policy and policing of zero tolerance for all Federal Government employees. Dr Lewis pointed out that this was never about occupational health and safety, but was a moral and political prerogative.
Urine is free, accessible, painless (generally) and has no 'matrix' problems, unlike saliva. It is backed up by good research and is medicolegally robust. However, it cannot determine the presence or absence of impairment, nor tell us about dose of drug or time of use. The cutoff levels set for identification of drugs are administrative levels, not indications of impairment.
In Australia the procedures surrounding urine testing (but not their interpretation or legal meaning) are governed by the Australian Standard AS4308, which Dr Lewis has been at the forefront of developing. It is important to ask whether labs are accredited to AS4308. There is a "loose association of drug screeners" LAD which work with accredited labs. The AS4308 does not lay down procedures for all drugs, for instance it covers amphetamine type substances ATS (previously called sympathomimetic amines), cannabinoids, and opiates (morphine, 6-acetylmorphine and codeine) but not opioids (such as methadone, oxycodone).
In considering the reliability of tests, especially on site testing, one must distinguish between accuracy (the trueness of the value around a cutoff figure) and precision (the ability of the test to achieve a consistent result every time). Ideally, a test is both accurate and precise, sadly often they are neither.
Dr Lewis gave examples where things go wrong - in bad hands testing results can be horrendous, and this extends to their interpretation. It is important to consult with experts.
One worker was sacked because of having a high urinary creatinine, which is an utter nonsense. Creatinine is essentially a measure of hydration, reflecting also muscle mass (likely to be low in thin Asian women, for instance). In another case, a person in a residential rehabilitation programme was disciplined after putting in positive urine tests for alcohol. However, the urine alcohol was 0.3, which would imply death in most people. On scrutiny, she was found to be diabetic, and sugar in her urine was fermenting to alcohol by the time it reached the lab.
The rights of employees are dealt with under the Privacy Act, which recognises, on balance, the appropriateness of drug testing for some people some of the time. A person tested has rights: to privacy in producing the urine test; to have the specimens correctly labelled and a referee sample provided; not to be accused of drug use on the basis of a urine test; and to challenge test a result.
Discussion followed of the reasons for the AS4308 setting (and most jurisdictions using) a cutoff concentration of 50 ng/mL for EIA for cannabinoids. This cutoff provides a good correlation with the GCMS confirmatory test for carboxy-THC 15: it is in this sense administratively reliable. It does not say anything about impairment, although correlates reasonably well with recent use. A negative test virtually excludes recent cannabis use.
A higher level of 100 ng/mL has also been used, and eliminates any possibility of a false positive test because of passive inhalation, however it will miss many cases of recent cannabis use.
Dr Lewis moved onto the possible benefits and limitations of saliva testing. Some of the issues:
- the possibility that saliva might correlate better with recent use and impairment;
- highly variable blood to saliva ratios from 1:2 to 1:5);
- the impairment caused by a drug such as methamphetamine can be most profound during withdrawal rather than intoxication - "and who is calling for an alco-hangover test", one person asked later. . most accidents caused by THC happened 2-4 hours after use of the drug, which was typically not detected in urine for 4-6 hours after a single consumption.
Dr Kyle Dyer, University of Western Australia, while noting that urine testing remains gold standard for various reasons, is hopeful of the eventual benefits of saliva testing. The evidence is currently limited, much of it produced by the testing industry rather than independent and objective researchers. Saliva concentrations are (variably) proportional to blood concentrations, and therefore a potentially better measure of free unbound drug (what actually gets into the brain), therefore of impairment (although unable to take into account tolerance to the drug). Most drugs, being bases, are passively diffused into saliva, the rate of this is affected by salivary pH. This was already a potential confounder, as the pH of 'stimulated' saliva is 7-8, compared with 'unstimulated' saliva (pH normally 5-5.7). Go stimulate your saliva. Saliva production averages 0.6 mls/minute (0.5-1.5 L/day) with a turnover time of about 10 minutes. Other methods for masking saliva tests were already being touted on the internet.
THC does not passively diffuse into saliva (there may be an active transporter). THC also 'sticks' in the mouth after smoking, also after passive smoking, which may cause a positive test. In general the window periods for detection for THC are short after low dose infrequent use, and earlier for saliva than urine.
Dr Dyer also has hopes for the benefits of saliva testing as a convenient and reliable indicator of plasma methadone concentrations for optimising methadone treatment.
Professor Steve Allsop, Director and Project Officer of the National Drug Research Institute spoke on "Testing the magic bullet. The potential and limitations of drug testing in the workplace.
In a time of changing mores (acceptability of workplace drug use; changes in prevalence and intensity of use), the things that will encourage responses to workplace substance use are a belief that there are real risks, and a responsibility to do something about it, and that there exist effective responses. He suggested we should target high prevalence areas, high harm drugs, and actual workplace risks. Thus, sorting alcohol problems in the workplace may have spin-off effects for other drugs.
Crucially, we should "resist bold claims where evidence is lacking".
In developing strategies, we need to remember the triangle of risk factors for substance use: the individual, the drug, and the environment, and act across all three of these. Connectedness with schools, communities and families reduces take-up of drug use. Substance use is an outcome of individual resilience, culture, and work structures (especially availability, supervision). Drug testing only targets the individual - it may have unintended and negative consequences (for example, removing all truckies with amphetamine type substances in urine tests might lead to higher workloads and increasing use of inexperienced drivers).
Professor Allsop said he would personally refuse a random drug test: if police need a warrant to search his house, they should certainly require one to test his body. In the case of Random Breath Testing, an impairment test would be best, but breath testing has the benefit of being practical. However he warned against using measures removed from the criteria we are interested in.
In the USA, the Council for Scientific Affairs (CAS) had officially pronounced that there is no association of drug screening tests with impairment. There was also little evidence of any benefit of drug testing. An example was pre-employment testing as a predictor of later workplace performance (including dropout): one study showed drug use was associated with poorer later workplace performance, but so too were black race and female gender. Another found a negative association for earlier school leaving age. Should these too be grounds for exclusion from work?
Declining levels of substances in the blood, and hangovers, may be higher risks than higher blood levels. There are quality assurance problems: false positives, handling and lab errors, also problems concerning over the counter (OTC) and prescription drugs. Should employers be privy to information about people's use of such substances?
There is no evidence of the cost-effective of drug testing. Too much emphasis on drug testing would parallel giving all resources to the police, rather than concentrating on the triple harm reduction goals of reducing demand, giving effective treatment, and interdiction. It might also undermine other responses, as the greatest benefits were to be had by keeping workers on side. Among other possible harms, people might respond by moving away from long half-life substances (such as cannabis) to short long half-life substances (such as cocaine or alcohol
There are lessons to be learned from OH+S (hard hats and steel cap boots are now associated with manliness) and public health (successful measures in reducing smoking have been based, not on testing, but on developing awareness of the risks to others - similarly with alcohol and RBT).
It was suggested from the floor that workplace drug testing is all about reducing financial risk and above all legal liability, an idea with which Professor Allsop agrees, although he noted that it is also embraced because of moralistic reasons; because of a belief that testing will promote changed behaviour; in response to statutory requirements, and sometimes because of the momentum of a "me too" effect. Dr Dyer suggested drug testing is a useful scapegoat: it is easy to blame the urine test for subsequent actions.
Is there value is determining "levels of impairment"? This requires measurement of baseline proficiency. Performance testing is still in its infancy. Experienced cannabis users do better on field sobriety tests than less experienced cannabis users. Dr Allsop suggested there is no acceptable level of impairment, and turned the question to one of where we best invest our efforts. There is a trade-off between level of evidence, level of intrusion and level of risk. The crucial issue is what members of the community are prepared to tolerate, and efforts were needed to ensure community support. He contrasted the community support for RBT with the general lack of support for speed cameras.
In later discussion, Professor Steve Allsop put his view on prohibition of cannabis: was it effective? NO; was it harmful? YES Did he support legalisation? NO. He believes it is unlikely that we could control that the cannabis industry (through regulation and taxation) as effectively as we do the tobacco and alcohol industries.
The following is an extract from the NCETA Information and Data Sheet Nr 4. Drug Testing as a response to Alcohol and Other Drug Issues in the Workplace
"... random testing can lead to an atmosphere of guilt and mistrust, which in turn can substantially impact on employee morale and motivation. This is especially the case if a positive test results in dismissal. When this occurs, employees may not see testing as a legitimate occupational health and safety or productivity issue. Rather, they may view testing as a disciplinary measure that extends employer control beyond the workplace into their private lives."
The transcripts of these presentations will be available from NCETA in the Proceedings of the Forum. For more details contact NCETA on 08 8201 7535 or nceta@flinders.edu.au or www.nceta.flinders.edu.au.
The forum presentations can be viewed at: www.nceta.flinders.edu.au/events/twenty_four_seven.html#Presentations
