Research Programme Operations. Updating drug and alcohol policies & testing methods

Transcription

1 Research Programme Operations Updating drug and alcohol policies & testing methods

2 Copyright RAIL SAFETY AND STANDARDS BOARD LTD ALL RIGHTS RESERVED This publication may be reproduced free of charge for research, private study or for internal circulation within an organisation. This is subject to it being reproduced and referenced accurately and not being used in a misleading context. The material must be acknowledged as the copyright of Rail Safety and Standards Board and the title of the publication specified accordingly. For any other use of the material please apply to RSSB's Head of Research and Development for permission. Any additional queries can be directed to research@rssb.co.uk. This publication can be accessed via the RSSB website:

3 Background...2 Introduction...3 Methodology...4 Findings...5 'Expert' views on potential lists of drugs to test for... 5 The availability of tests for potential drugs to be tested for... 8 Technical detail relating to drug testing...11 Summary Frequently asked Questions (FAQ)...15 Updating the list of core drugs Passive smoking defence Testing of individuals who eat poppy seed products Countering adulteration of samples Possible changes to testing times and regimes Appendix 1: Likelihood of a drug having been taken...19 Appendix 2: Sensitivity and Specificity of Screening Tests...21 References...22

4 Updating drug and alcohol policies & testing methods Prepared by Sharon Allaway, MARUM HEALTHCARE Ltd RSSB 1

5 Updating drug and alcohol policies & testing methods Background The Railway Group Standard GE/RT Testing railway safety critical workers for drugs and alcohol - requires train infrastructure managers and railway undertakings to carry out drug and alcohol testing of staff carrying out safety critical work. The document was issued in December 2008 and came into force in February It assumes the following: that each organisation has an established drug and alcohol policy that each organisation carries out drug and alcohol tests prior to staff being appointed as well as regular and systematic monitoring including, 'For cause' testing. As the standard is 'a mandatory document which sets out the minimum requirements to ensure system safety and safe interworking on the mainline railway', it does not contain technical information such as a list of drugs to be tested for. Guidance on the Management of Drugs and Alcohol (GE/ GN8570) was issued and came into force at the same times as the standard. This is intended to help railway undertakings and infrastructure managers to meet the requirements of both the Transport and Works Act 1992 and GE/RT8070. The document whilst giving organisations some practical detail regarding key components of a system to manage drug and alcohol misuse makes it clear that each organisation has to identify such things as the list of drugs to test for, and methodology used for testing. 2 RSSB

6 Introduction In October 2008, the Association of Train Operating Companies (ATOC) approached the Rail Safety and Standards Board (RSSB) about undertaking a small piece of research to pull together the most recent ideas concerning both a core list of drugs to be tested for and the most appropriate methodology for measuring the drugs identified. RSSB agreed to the request on the basis that the outcomes of previous work done in this area (2004) may need updating. ATOC identified the benefits of undertaking this research would be: 1 To overcome the present lack of core consistency between TOCs in respect of their drug and alcohol policies which can determine a Whether or not an employee loses his / her job b Whether an accident might be caused or avoided. 2 To provide clear evidence on which an up to date policy on testing methods can be established and used by TOCs as appropriate. RSSB 3

7 Updating drug and alcohol policies & testing methods Methodology Desk-based research covering the following areas was undertaken by Marum Healthcare Ltd: 'Expert' views on potential list of drugs to test for The availability of tests for each potential drug listed Technical detail relating to drug testing The findings were presented to the ATOC HR Directors Forum on 13 March The following report comments in more detail on each of the above mentioned areas covered in the presentation. Each subsection of the report (covering one area) contains a summary listing issues for consideration by ATOC and the TOCs. The report also includes a list of Frequently Asked Questions (FAQs) relevant to this topic area. Most were raised at the 13 March 2009 meeting. 4 RSSB

8 Findings This section covers the findings of the three areas 'Expert' views on potential list of drugs to test for The availability of tests for each potential drug listed Technical detail relating to drug testing 'Expert' views on potential lists of drugs to test for 1 RSSB Projects. The reports from T050 - 'Survey of policies relating to alcohol and substance abuse in a range of industries' and T133 - 'Review of drug testing methodologies' include lists of drugs that are commonly tested for in workplace drug screening programmes. 2 RSSB's Medical Adviser. The adviser suggested in a paper on drug testing 1, 'a typical screening panel of drugs in use within the rail industry might include: cannabis, cocaine, opiates, phencyclidine, amphetamines (including methyl amphetamine and MDMA/ecstasy), barbiturates, benzodiazepines, methadone and buprenorphine'. 3 Workplace D&A Consultant. The view of the consultant articulated at a recent meeting 2 is that the following drugs should be included in a workplace drug screening programme together with any drugs known to be used specifically in a particular geographical area and/or by the age group and social class being tested. 4 UIC Occupational Health and Safety Group. This group listed a number of drugs commonly tested for in Europe in its recent document, 'Developing management arrangements for the Control of Safety Risks related to the Influence of Alcohol, Drugs and/or Psychoactive Medication', published in February Which drugs should be tested for? February Managing Alcohol & Drugs in the Workplace meeting - November 2008 RSSB 5

9 Updating drug and alcohol policies & testing methods Table 1 - Summary of Expert views on potential list of drugs to test for: Drugs * depending on assessment probably be added on request of workplace - screening assay not readily available part of some screening panels a metabolite of heroin Source of expertise RSSB T050 RSSB T133 RSSB Medical Adviser Workplace D&A Consultant UIC OH&S Group Amphetamines Barbiturates * Benzodiazepines * Buprenorphine Cannabis / cannabinoids Cocaine & metabolites Ecstasy (MDMA) Methadone * Opiates incl. 6-MAM Propoxyphene Phencyclidine Other drugs of choice in area [Alcohol] Furthermore, laboratories providing workplace drug testing services will be able to advise individual TOCs which drugs are responsible for the greatest proportion of positive results, and therefore should be considered for inclusion in a drug-testing regime. 6 RSSB

10 Summary ATOC / TOCs need(s) to bear in mind the following when compiling a core list of drugs from Table 1: The likelihood of a drug been taken; see Appendix 1. Whether a test exists; see next section, 'The availability of tests for potential drug to be tested for' The ability of a drug to affect performance detrimentally 3 i.e. the purpose for authorising the test is not to test for an illegal substance. The choice of drugs to be included in a testing programme is only useful if a sufficiently high proportion of workers are tested, and random testing is truly unannounced 4 ; see also Summary on page 11. That the choice of drugs should be revisited from time to time to ensure the list remains current. Transport for London is currently considering the inclusion of Ketamine in their screening panel as a result of declarations made in the last year by employees seeking help with an addiction 5. 3 The topic of which drugs are likely to cause impairment falls outside the remit of this report and has been reported on by HSE in their Research Report Series RR193 (2002) The scale and impact of illegal drug use by workers. 4 Oral fluid (OF) detection times tend to be shorter than urine therefore the extent of pre-warning that an individual may receive concerning a random test must be short. However, as no special collection facilities are needed for OF testing, setting up Random and 'For Cause' testing should be more straightforward. 5 Information with thanks from Dr Olivia Carlton, Head of Occupational Health, TfL RSSB 7

11 Updating drug and alcohol policies & testing methods The availability of tests for potential drugs to be tested for Table 2 - Non-exhaustive list of drugs / drug groups for which screening kits a available Drugs Sampling media that can be used Blood Urine Oral Fluid Hair / Nails Amphetamines Barbiturates Benzodiazepines Buprenorphine Cannabis / cannabinoids Cocaine & metabolites Ecstasy (MDMA) Methadone Opiates incl. 6-MAM Propoxyphene Phencyclidine Other drugs of choice in area [Alcohol] a. Immunoassays - homogenous and Enzyme-linked immunosorbant assays (ELISA) 1 Positive test. A positive test indicates the presence of an illegal substance only. It does not give any indication of the degree of impairment. 2 Positive result. A positive result can only be conferred by a Medical Review Officer (MRO). All positive tests are referred to a MRO who will then undertake a review to ensure whether there are reasons other than the use of an illegal drug that could account for the positive finding. Should there be none the positive test will be reported as a positive result to the organisation, which will then need to deal with it in accordance with their policy. 8 RSSB

12 3 General detection time for drugs in blood, oral fluid, urine, sweat and hair. Levels of drugs can be detected almost immediately following consumption in both blood and oral fluid. In fact, the good relationship between the concentration of a drug in the blood and in oral fluid have led to the suggestion that drug levels in oral fluid may be a better reflection of likely drug-induced impairment or effect than urine measurement, as there is generally a time lag of several hours before the drug / metabolites appear in urine. For example, a 4-hour time delay has been noted post the smoking of marijuana for the appearance of cannabis metabolites (cannabinoids) in the urine. Drugs are generally detected in sweat anywhere between 2-8 hours after ingestion and it will take 3-5 days for the hair to grow sufficiently long for the drug to appear at the skin surface (Karch, 2008). Figure 1 shows more detailed information relating to named drugs 6. 6 The detail in the chart is an amalgamation of data from several reference documents [Fit4 Duty detection times (2006), Access Diagnostics Drug Detection Times (2008), Ultimate Detox Drug Detection Times (2007) and others including the T133 report] and is indicative of the relative lengths of windows of detection for measuring various drugs in different biological samples RSSB 9

13 Updating drug and alcohol policies & testing methods Figure 1 - Detection Windows for specific drugs. Summary ATOC / TOCs need(s) to bear in mind the following when updating policy on testing methods: Detection times reported for drugs in any sampling media vary considerably according to the individual's metabolism, the dose, their drug taking history and possibly the route of abuse. For more detail see the next section. A blood or oral fluid sample would probably provide the most accurate evidence that a person was under the influence of drugs or alcohol for a 'For Cause' or 'Post Incident' test whereas a positive urine test would generally indicate an illegal drug had been taken some time within the past day. Hair tests are generally used to monitor long term trends of use / abstinence from use, of illegal drugs. 10 RSSB

14 Technical detail relating to drug testing 1 Technique used. a Screening Test. Immunoassay techniques are used to test both urine and oral fluid samples for the drug or drug metabolites of interest. These tests generally work in the following way - an antibody (plus indicator) to the drug / metabolite to be tested for is mixed with the sample (OF or urine) in a 'test well'. If the drug is present in the sample the antibody binds to the drug / metabolite and becomes fixed in the 'test well'. A mild acid is then added to the mixture which reacts with the indicator to produce a coloured compound, the optical density of which is measured. The amount of colour produced is proportional to the amount of drug / metabolite present. b Confirmatory Test. This is carried out in all instances where a screening test indicates a positive result. The test uses a mass spectrometric technique that can identify and measure the actual amount of drug / metabolite present in the sample. 2 Robustness of the tests. There are a number of ways in which the robustness of the analytical assays used to test for drugs / metabolites are determined: a Sensitivity. This measure relates to the number of positive tests an assay such as the Screening Test (mentioned above) identifies as positive compared to a 'gold standard assay', which in the context of workplace drug testing is Gas Chromatography - Mass Spectrometry. b Specificity. This measure relates to the number of negative tests an assay such as the Screening Test, identifies as negative with reference to a 'gold' standard assay'. See Appendix 2 for worked example. An ideal screening test is both sensitive and specific and the agreed cut-off levels for each of the drugs / metabolites measured are designed to ensure the best sensitivity and specificity for the assay used. c False Positive. This is a measure of the number of tests that are identified as positive by a screening test but negative by a confirmatory test. False positive results for illicit drugs have been known to be caused during particular work-up for analytical RSSB 11

15 Updating drug and alcohol policies & testing methods procedures, which explains why considerable work continues to be undertaken to ensure that methods as far as reasonably practicable distinguish between illicit drugs and closely related drugs that may have legitimate prescribed or 'Over the Counter' origins. d False Negative. This is a measure of the number of tests that are identified as negative by the screening test and positive by the confirmatory test. Detection limits applied to the confirmatory test are usually set such that this event rarely occurs. 3 Substance Measured. a In oral fluid (OF). Drugs can be detected in this medium almost immediately following consumption whereas for some drugs there is almost no appearance of breakdown products (metabolites) in OF e.g. cannabis. Thus the parent compound is usually targeted in both the screening and confirmatory tests. 6-acetyl morphine (6-MAM), a metabolite of heroin that will only be detected if the drug has been taken 7, can be measured in both OF and urine for a period of between 2-8 hours. b In urine. In many instances the amount of the parent drug that can be detected in urine several hours after ingestion is small or non-existent relative to the amount of metabolites. Hence, principal metabolites of illegal drugs are usually measured in urine. For example, only the metabolites of heroin can be measured in the urine. 4 Window of Detection. When determining sampling strategies for screening and confirmatory testing programmes scientists must take into account a number of factors that can affect the result of the test. For example: a Whether the parent compound or metabolites are being measured. See 3. b Dose of drug used. Single isolated small doses of an illegal drug are generally detectable for short periods only, whereas chronic and long-tem use generally results in detection of an illegal drug for longer periods of time; see also (4.e). 7 6-MAM will not be detected by a person consuming poppy seeds 12 RSSB

16 c d e f g Analytical sensitivity of the test. Testing equipment can be sensitive enough to detect very low levels of substance that have found their way in to the body other than through illicit drug use i.e. tests can be too sensitive. Timing and level of cut-off for a test are of critical importance in ensuring that the majority of positive tests that are recorded arise from the use of an illegal drug or a legal drug taken in unwarranted quantities. For example, although cannabis can be detected in an OF sample immediately after use, a measurement taken more than 1hour later will give an indication of whether the drug was taken intentionally or not 8, in the same way that the breath alcohol level measured after 20 minutes reflects alcohol ingested rather than alcohol produced naturally in the mouth. Cut-off level applied in defining a positive result. Heroin is broken down (metabolised) rapidly to produce morphine and a number of other metabolites. Morphine can also be found in the body as a result of ingesting poppy seeds. To overcome the recording of a positive test for the licit taking of drugs cut-off levels have been raised to a point where the vast majority of licit use is screened out; see FAQ Testing of individuals who eat poppy seed products Habitual use versus occasional use of drugs. Chronic users with a high tolerance to their drug of choice may well eliminate drugs quicker than an occasional user. See also (4b) above. Individual's metabolic status. Both increasing age and increasing body mass slow down human metabolism and individuals with slower body metabolism tend to eliminate drugs over a longer time span. Route of misuse. Smoking of certain drugs eg cannabis, leads to a deposit of drugs in the mouth, which is additional to any mechanism of transfer of the drug from blood to OF. The deposition mechanism may lead to higher OF concentration of drug than would be predicted by blood concentration shortly after smoking 8 Research has shown that tests for the inhalation of cannabis passively will be negative within 50 minutes of exposure. RSSB 13

17 Updating drug and alcohol policies & testing methods and a consequential lengthening of the window of detection. Likewise, the 'sniffing' or 'snorting' of drugs leads to deposits in the nasopharyngeal cells which can lead to high levels in OF and an extended window of detection. Cannabis ingestion also leads to a significant window of detection for OF and urine measurements. Summary ATOC / TOCs need(s) to bear in mind the following generality relating to sample testing: Screening and Confirmatory testing are not 100% accurate as there is a trade off between the sensitivity and specificity of a test and the relative rate of each depends on the proportion of the population being tested that are likely to be positive. Hence, the Medical Adviser's statement 'that the choice of drugs to be included in a testing programme ' see Summary on page RSSB

18 Frequently asked Questions (FAQ) Updating the list of core drugs The British Crime Survey reports annually on the percentage of year olds admitting to taking illegal drugs in the past year (see Appendix 1). The survey is quite comprehensive with regard to the range of drugs that have been taken by the population as a whole since To date, the survey has shown no real changes to the drugs of choice abused over the time period covered and it would be relatively straightforward for the RSSB's research team to update the chart in appendix 1 annually following the release of the survey. However, the distribution may not be directly relevant to a working population in the railway industry. An exercise that could produce more insightful information for TOCs would be to amalgamate information collected by their HR / OH teams annually regarding the drugs of use employees who seek help for addiction problems admit to using. Should this be of interest, RSSB will consider undertaking such a survey. Passive smoking defence Testing of individuals who eat poppy seed products The literature suggests that positive drug tests for cannabis in both urine and oral fluid could occur following heavy passive smoking of cannabis but during and only for a short time frame (less than 1 hour) immediately following exposure. It is unlikely the conditions under which the experiment was carried out - 4 passive smokers plus 5 active smokers and a team of researchers housed in a very small room (36m3) in which the doors and window openings sealed for four hours - would ever be replicated in the railway work environment. Hence positive tests would be most likely explained by a pro-active decision of the individual to take the drug. The poppy seed defence could be a legitimate one as a number of studies have shown morphine levels greater than the usual cutoff level for morphine in both OF and urine samples in those eating foods containing poppy seeds. The experiments showed that an individual eating two rolls covered with poppy seeds (equivalent to four grams of seeds) would produce a positive OF RSSB 15

19 Updating drug and alcohol policies & testing methods sample for up to one hour after ingestion and a positive urine sample for up to eight hours after ingestion. However, samples from individuals who have only ingested poppy seeds are never positive for 6-acetyl morphine which is a breakdown product of heroin only. Countering adulteration of samples Urine. The predominant use of urine testing has led to the development of a largely US internet-based counter industry offering products and techniques for deliberately suborning urine drug tests. Collectors and laboratories can help to counter this behaviour through pragmatic measures such as, use ofspecialised toilet facilities and immediate testing of urine temperature to identify urine substitution, as well as the measurement of marker chemicals or properties of the sample such as urinary creatinine 9 and the SG (specific gravity) to detect dilution etc. The measurement of marker chemicals relies on the fact that these are present in the body at constant levels in the absence of a disease and that dilution of a sample will also dilute the concentration of these chemicals altering the laboratory to investigate further. Oral Fluid. Many believe it is more difficult to adulterate an oral fluid sample for the following reasons - collectors can do an oral cavity check prior to the taking of the sample; subjects can be made to wash out their mouths with water and then wait a defined length of time before the sample is taken and the collection of the sample can be viewed by a second person without infringing privacy. Laboratories are able to measure the ph of a sample to determine whether it is in the normal range ( ) and they can also measure protein levels found in oral fluid - IgG and Gingival Crevicular Factor (GCF) - to determine if a sample has been deliberately diluted; see explanation above. 9 Creatine is synthesized from amino acids in the kidney, liver and pancreas. The creatine is then transported in the blood to other organs where it is synthesized into creatinine. In the absence of kidney disease, the urinary creatinine is excreted in rather constant amounts and represents glomerular filtration and active tubular excretion of the kidney 16 RSSB

20 Even if it were not possible to do any of the above, extensive testing has shown that possible adulterants such as sugar water, toothpaste, baking soda, mouth wash etc. do not interfere with the performance of the immunoassay. Neither do these agents produce false positive results in the immunoassay. Possible changes to testing times and regimes Laboratory blind analysis testing. UK NEQAS (National External Quality Assurance Scheme) are due to launch proficiency testing of drug detection in oral fluid samples in Quarter 2 of 2009 following the completion of a very successful pilot study in which 20 laboratories around Europe participated. This will allow UK laboratories to offer a service to TOCs that complies with requirement 2.2 of RGS GE/8070 that states, infrastructure managers and railway undertakings shall only use laboratories for drug and alcohol analysis that are UKAS accredited and subject to blind analysis testing under an external quality assurance scheme. Sample collection. The United Kingdom Workplace Drug Testing Forum (UKWDTF) is in the process of finalising guidelines for oral fluid testing which will recommend that the collection devices used must collect a known volume of exudate (sample). This will allow precise calculation of levels of substance found in samples which can then be compared to the cut-off levels used to determine if a result is negative or positive. Use of oral fluid testing to detect cannabis. Information from a number of sources indicate that testing for cannabis in OF is methodologically sound. References include: Drug Testing in Oral Fluid by Olaf H Drummer (Clin Biochem Rev Vol 27 August 2006) The potential of oral fluid as a specimen in various drug testing programs by Christine Moore et al. Proficiency testing (external quality assessment) of drug detection in oral fluid by Joe Clark & John Wilson (Forensic Science International 2005) Detection of Marijuana by oral fluid and urine analysis following single-dose administration of smoked and oral marijuana by R S Niedbala et al (J Analytical Toxicology Vol 25 August 2001). Management systems for undertaking drug testing. TOCs wishing to use OF testing to meet their obligations will have to RSSB 17

21 Updating drug and alcohol policies & testing methods ensure that their systems are set up to collect samples within the window of detection for the drugs tested for. Suggested changes to help accommodate this include: Testing employees for drug misuse when they arrive at work Removing the pre-warning of random drug testing Social and cultural Issues. There are at least two issues that may make it increasingly difficult for TOCs to continue using urine samples for drug and alcohol testing purposes Australian unions have vetoed urine testing as derogatory. Muslim women's needs for modesty. 18 RSSB

22 Appendix 1: Likelihood of a drug having been taken The British Crime Survey is a large survey of a representative sample (> 51,000) of people aged 16 and over living in private households in England and Wales that is carried out every year, which ask amongst other things about people's use of illicit drugs. Figure 2, plots the percentage of year olds who said they had used drugs in the last year, from /08. Figure 2 - Percentage year olds admitting to taking illegal drugs /08 NB. The term Tranquillisers covers the drug groups Barbiturates and Benzodiazepines The survey identifies the top drug of choice used by the general UK population - cannabis - is used by significantly more people and more frequently than any other illicit drug. Statistically significant changes in use were noted for cocaine, ecstasy, amphetamines and cannabis between 2006/07 and 2007/08. All changes were in a downward direction. There were no changes in the level of use of the other drugs charted. RSSB 19

23 Updating drug and alcohol policies & testing methods The use of ketamine (not charted) was first recorded by the survey in 2006/07. A recent Drugscope survey found the use of this drug was on the rise in nine out of 20 areas survey around the country although the British Crime Survey showed there has been no statistically significant change in use to date. 20 RSSB

24 Appendix 2: Sensitivity and Specificity of Screening Tests SENSITIVITY is the proportion of positive confirmatory test results for which there was also a positive screening test result. SPECIFICITY is the proportion of negative confirmatory test results for which there was also a negative screening test result. RSSB 21

25 Updating drug and alcohol policies & testing methods References Karch, Steven B Workplace Drug Testing. (2007) RSSB, T133 Review of drug testing methodologies. (London, 2004) 22 RSSB

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27 RSSB Research Programme Block 2 Angel Square 1 Torrens Street London EC1V 1NY research@rssb.co.uk