Tom Blencowe

An analytical evaluation of eight on-site oral fluid drug screening devices using laboratory confirmation results from oral fluid

The performance of eight on-site oral fluid drug screening devices was studied in Belgium, Finland and the Netherlands as a part of the EU-project DRUID. The main objective of the study was to evaluate the reliability of the devices for testing drivers suspected of driving under the influence of drugs (DUID). The performance of the devices was assessed by their ability to detect substances using cut-offs which were set at sufficiently low levels to allow optimal detection of positive DUID cases. The devices were evaluated for the detection of amphetamine(s), cannabis, cocaine, opiates and benzodiazepines when the relevant test was incorporated. Methamphetamine, MDMA and PCP tests that were included in some devices were not evaluated since there were too few positive samples. The device results were compared with confirmation analysis results in oral fluid. The opiates tests appeared to perform relatively well with sensitivity results between 69 and 90%. Amphetamines and benzodiazepines tests had lower sensitivity, although the DrugWipe test evaluated was promising for amphetamine. In particular, it is evident that the cannabis and cocaine tests of the devices still lack sensitivity, although further testing of the cocaine tests is desirable due to the low prevalence and low concentrations encountered in this study.

Alcohol and drugs in seriously injured drivers in six European countries

The objective of this study was to determine the presence of alcohol and drugs in drivers severely injured in traffic crashes in six European countries. Data were collected from 2492 seriously injured drivers of cars and vans in Belgium, Denmark, Finland, Italy, Lithuania, and the Netherlands, between 2007 and 2010. Toxicological analysis was performed with chromatographic techniques on whole blood for 23 substances. The percentage of drivers positive for at least one psychoactive substance ranged between 28% (Lithuania) and 53% (Belgium). Alcohol (≥0.1 g/L) was the most common finding with the highest percentage in Belgium (42.5%). Among the alcohol-positive drivers, 90.5% had a blood alcohol count (BAC) ≥0.5 g/L and 65.7% had a BAC ≥1.3 g/L. Benzodiazepines (0.0-10.2%) and medicinal opioids (0.5-7.8%) were the most prevailing medicinal drugs, but half of the concentrations were lower than therapeutic. Cannabis (0.5-7.6%) was the most prevailing illicit drug. Alcohol was found in combination with drugs in 2.3-13.2% of the drivers. Drug combinations were found in 0.5-4.3% of the drivers. This study confirms the high prevalence of psychoactive substances in injured drivers, but we observed large differences between the participating countries. Alcohol was the most common finding, followed by cannabis and benzodiazepines. Notable are the many drivers having a BAC ≥ 1.3 g/L. The majority of the substances were found in combination with another psychoactive substance, mostly alcohol. The high prevalence of high BACs and combinations (compared to roadside surveys) suggest that those drivers are most at risk and that preventive actions should target them preferentially.

Benzodiazepines and sedative-hypnotics in blood of drivers under the influence and their association with other common illegal drug use and national sales figures.

The authors examined benzodiazepine and sedative-hypnotic positive cases of drivers under the influence (DUI) in Finland from 1997 to 2008. Factors studied were the number of cases positive for the most commonly encountered of these pharmaceuticals, simultaneous use of amphetamine and/or cannabis, and the relationship between the number of DUI cases and overall sales in Finland for the individual pharmaceuticals. Data for 20037 cases positive for the relevant drugs were retrieved from the laboratory database of the Alcohol and Drug Analytics Unit, National Institute for Health and Welfare. Toxicological results were from blood analysis. Drug sales figures for each pharmaceutical were obtained from the Finnish Medicines Agency. An increase in DUI cases that were positive for the drugs studied was evident, which reflected the overall increase in positive DUI cases detected annually. The proportion of relevant cases was typically 75% or higher of all positive DUI cases up to 2003, the year that the Finnish zero tolerance law was introduced, and then decreased to 66.2% in 2008. Diazepam was consistently the most commonly detected nonmetabolite drug. The prevalence of clonazepam and alprazolam increased sharply from 2004 onward. Metabolites of diazepam, nordiazepam, temazepam, and oxazepam, were other common findings. Associated use of amphetamine and/or cannabis was also common in these DUI cases, typically between 56% and 66% of cases. An increase in the number of DUI cases showing combined use of benzodiazepines and sedative-hypnotics with amphetamines in particular was apparent after zero tolerance legislation and the introduction in 2005 of an effective on-site screening device for the stimulant. Ratios of DUI cases to sales figures showed an increase in detection of clonazepam-positive DUI cases from 2003. Diazepam, midazolam, and alprazolam also exhibited relatively high ratios, which increased from 1997 to 2008.

Performance evaluation of the DrugWipe® 5/5+ on-site oral fluid screening device

This study presents a retrospective performance evaluation of an on-site oral fluid drug screening device DrugWipe® 5/5+ (Securetec). The results obtained by the device were compared with gas chromatography–mass spectrometry confirmation analysis results in whole blood. Data used in the comparison were based on 1,807 real cases in which the Finnish police had conducted an on-site drug test on persons suspected of driving under the influence of drugs. The present data cover only cases wherein the DrugWipe device has shown a positive result for at least one substance. The data were compiled from the databases of Alcohol and Drug Analytics Unit at the National Institute for Health and Welfare. The performance of the DrugWipe was evaluated for its relevant drug groups: amphetamines, cannabis, opiates, and cocaine. The evaluation was carried out by calculating the sensitivity, specificity, and accuracy as well as the positive and negative predictive values. These calculations were based on the classification of the results as true positives, false positives, true negatives, and false negatives. Additionally, the demographics of the cases and analytical findings in whole blood are discussed. According to this study, the DrugWipe device performed quite well in detecting amphetamines, the most frequently encountered group of illicit drugs in Finnish traffic. The performance of the cannabis, opiate, and cocaine tests was not at the same level.