Toxicology findings from drivers suspected of drug-impaired driving in Ontario (2008-2019).

OBJECTIVE: This study examines the results of toxicological tests performed on blood and urine samples collected from suspected drug-impaired drivers in Ontario from 2008 to 2019. The report examines the results of toxicological analysis of the samples submitted, the characteristics of those drivers from whom samples were collected, and the temporal and situational circumstances that led to police investigations and sample collection to better understand drug-impaired driving behavior and to assist in the development and implementation of countermeasure strategies and programs. METHODS: Blood and urine samples were sent to the Center of Forensic Sciences where they were analyzed using standardized comprehensive toxicological analysis to test for a wide variety of potentially impairing drugs. Demographic and temporal information for each case from which a sample was collected were also examined to describe the circumstances and characteristics of these driving incidents. RESULTS: During the 12-year period examined, 5,388 samples collected from suspected drug-impaired drivers were analyzed. The number of samples collected increased substantially following the implementation of the Drug Evaluation and Classification Program (DECP) in July 2008, the enactment of legislation facilitating the collection of blood samples from suspects, and the legalization of cannabis for nonmedical purposes in 2018. The number of samples submitted shows temporal correlation with the number of police officers certified as Drug Recognition Experts (DRE) in the province. Over the 12-year period of this study, cannabis was the most frequently detected substance in drivers (52.8% of cases), followed by cocaine (44.3%) and methamphetamine (24.8%). In 80% of cases, more than one substance was detected. CONCLUSIONS: Examining the characteristics of suspected drug-impaired drivers, the temporal circumstances, and the drug findings throughout the large geographic area of Ontario and over the extended period of this study enhances our understanding of drug-impaired driving behavior. These characteristics can assist in the development and/or evaluation of enforcement strategies and enhanced countermeasure activities.

Enhancing the Standardized Field Sobriety Test to detect cannabis impairment: An observational study.

OBJECTIVE: The purpose of this study was to explore various tests of impairment that could potentially be added to the Standardized Field Sobriety Test (SFST) to enhance its sensitivity to identify drivers whose abilities are adversely affected by cannabis. METHODS: An observational study was conducted in which participants were invited to use their own cannabis at the research facility. Once prior to cannabis use and at four times during the 150 min after cannabis use, participants performed the three tests of the Standardized Field Sobriety Test (SFST) (i.e., Horizontal Gaze Nystagmus, Walk and Turn, and One Leg Stand) as well as the Modified Romberg Balance and Finger to Nose tests. In addition, assessments were made of physiological indicators (i.e., eyelid, leg and body tremors, rebound dilation, lack of convergence) and vital signs (pulse, blood pressure and body temperature). Participants also completed a digit-symbol substitution task at each testing interval. With the exception of vital signs and the digit symbol task, all tests and assessments were administered and scored by certified Drug Recognition Experts using the standard procedures of the Drug Evaluation and Classification Program. RESULTS: Twenty minutes after vaping cannabis (mean THC concentration = 6.34 ng/mL), participants displayed performance deficits on a variety of tasks; 67% met the criterion for suspected impairment on the SFST. Addition of the Finger-to-Nose (FTN) test along with observations of head movements and jerks (HMJ) increased the percentage of participants who met the criterion for suspected impairment by 33% and improved the sensitivity of the test from 0.67 to 0.88. CONCLUSIONS: The results of this study support supplementing the SFST with the Finger-to-Nose test and observations of HMJ to assist in the detection of drivers who are adversely affected by the use of cannabis. The observational study design and the use of assessors who were not blinded as to the use of cannabis by participants limits the strength of the evidence. Further research, including randomized trials and field studies of drivers, is required to confirm and validate this enhanced version of the SFST.

Cannabis, alcohol and other drug findings in fatally injured drivers in Ontario.

OBJECTIVE: The purpose of this study was to determine the prevalence of cannabis, alcohol and other drug use in drivers of motor vehicles who died in crashes in the Canadian province of Ontario from January 2016 through December 2018 along with the characteristics of these drivers and some of the circumstances of the crash in which they were involved. METHODS: Toxicological tests were performed on blood samples obtained from 921 driver fatalities for whom postmortem blood samples were submitted to the Center of Forensic Sciences for analysis. The results were coded into a database along with basic demographic and crash characteristics and examined for prominent characteristics and patterns. RESULTS: Overall, among the 921 cases examined, 495 (53.7%) tested positive for alcohol, cannabis (tetrahydrocannabinol or THC), or another psychoactive drug. The number of cases that tested positive for THC (251) exceeded the number of cases that tested positive for alcohol (241) as well as the number that tested positive for a drug other than THC (235). In 38% of positive cases, more than one substance was detected. Alcohol and THC were most commonly detected among males; females most frequently tested positive for a drug other than THC, notably medications with depressant effects. Alcohol-involved driver fatalities were most common on weekends and most likely involved single vehicle crashes. Driver fatalities that tested positive for THC or another drug were more evenly distributed throughout the week and were more likely to have been in multi-vehicle crashes. CONCLUSIONS: The present study highlights the use of cannabis and other drugs by drivers. The patterns of crashes and the characteristics of drivers involved indicate that the characteristics of driver fatalities involving cannabis and/or other drug use differ from those of alcohol and require new, innovative approaches targeting high-risk times, groups and behaviors. Continued monitoring of the toxicological findings from blood samples obtained from drivers killed in motor vehicle crashes will be a key element in efforts to reduce the impact of drug use by drivers on road safety.

Predicting categories of drugs used by suspected drug-impaired drivers using the Drug Evaluation and Classification Program tests.

Objective: The purpose of this study was to statistically determine which combination(s) of drug-related signs and symptoms from the Drug Evaluation and Classification (DEC) protocol best predict the drug category used by the suspected drug-impaired driver. Methods: Data from 1,512 completed DEC evaluations of suspected impaired drivers subsequently found to have ingested central nervous system (CNS) depressants, CNS stimulants, narcotic analgesics, and cannabis were analyzed using a multinomial logistic regression procedure. A set of evaluations completed on drug-free subjects was also included. The relative importance of clinical, behavioral, and observational measures in predicting drug categories responsible for impairment was also examined. Results: Thirteen drug-related indicators were found to significantly contribute to the prediction of drug category, including being under the care of a doctor or dentist, condition of the eyes, condition of the eyelids, mean pulse rate, assessment of horizontal gaze nystagmus (HGN), convergence, performance on the One Leg Stand (OLS) Test, eyelid tremors, pupil size in darkness, reaction to light, presence of visible injection sites, systolic blood pressure, and muscle tone. Indicators related to the appearance and physiological response of the eye contributed the most to the prediction of drug category, followed closely by clinical indicators and performance on the psychophysical tests. Conclusions: The findings from this study suggest that drug recognition experts (DREs) should be careful to review a set of key signs and symptoms when determining the category of drug used by suspected drug-impaired drivers. Drug use indicators related to the appearance and physiological response of the eye were found to contribute the most to the prediction of the drug category responsible for the impairment. These results could help form the basis of a core set of indicators that DREs could initially consult to form their opinion of drug influence. This in turn may enhance the validity, effectiveness, and efficiency of drug detection and identification by DREs and lead to a more effective and efficient DEC program, improved enforcement of drug-impaired driving, and greater acceptance of the DEC program by the courts.

Can progress in reducing alcohol-impaired driving fatalities be resumed? Results of a workshop sponsored by the Transportation Research Board, Alcohol, Other Drugs, and Transportation Committee (ANB50).

OBJECTIVE: Despite successes in the 1980s and early 1990s, progress in reducing impaired driving fatalities in the United States has stagnated in recent years. Since 1997, the percentage of drivers involved in fatal crashes with illegal blood alcohol concentration (BAC) levels has remained at approximately 20 to 22%. Many experts believe that public complacency, competing social and public health issues, and the lack of political fortitude have all contributed to this stagnation. The number of alcohol-related crashes, injuries, and fatalities is still unacceptable, and most are preventable. The public needs to be aware that the problem presented by drinking drivers has not been solved. Political leaders need guidance on which measures will affect the problem, and stakeholders need to be motivated once again to implement effective strategies. METHODS: The National Academy of Sciences (NAS) Transportation Research Board (TRB), Alcohol, Other Drugs, and Transportation Committee (ANB50) sponsored a workshop held at the NAS facility in Woods Hole, Massachusetts, on August 24-25, 2015, to discuss the lack of progress in reducing impaired driving and to make recommendations for future progress. A total of 26 experts in research and policy related to alcohol-impaired driving participated in the workshop. The workshop began by examining the static situation in the rate of alcohol-impaired driving fatal crashes to determine what factors may be inhibiting further progress. The workshop then discussed 8 effective strategies that have not been fully implemented in the United States. Workshop participants (16 of the 26) rated their top 3 strategies. RESULTS: 3 strategies received the most support: 1. Impose administrative sanctions for drivers with BACs = 0.05 to 0.08 g/dL. 2. Require alcohol ignition interlocks for all alcohol-impaired driving offenders. 3. Increase the frequency of sobriety checkpoints, including enacting legislation to allow them in the 11 states that currently prohibit them. 5 other important strategies included the following: (1) increase alcohol taxes to raise the price and reduce alcohol consumption; (2) reengage the public and raise the priority of impaired driving; (3) lower the illegal per se BAC limit to 0.05 for a criminal offense; (4) develop and implement in-vehicle alcohol detection systems; and (5) expand the use of screening and brief interventions in medical facilities. CONCLUSIONS: Each of these strategies is proven to be effective, yet all are substantially underutilized. Each is used in some jurisdictions in the United States or Canada, but none is used extensively. Any one of the 3 strategies implemented on a widespread basis would decrease impaired driving crashes, injuries, and fatalities. Based on the research, all 3 together would have a substantial impact on the problem.

An examination of the validity of the standardized field sobriety test in detecting drug impairment using data from the Drug Evaluation and Classification program.

OBJECTIVE: The purpose of this study is to assess the validity of the 3 components of the Standardized Field Sobriety Test (SFST), including the Horizontal Gaze Nystagmus (HGN), One Leg Stand (OLS), and Walk and Turn (WAT) tests, in identifying impairment among suspected drug-impaired drivers using data recorded during drug evaluation and classification (DEC) evaluations. METHODS: Data from 2142 completed DEC evaluations of central nervous system (CNS) stimulants, CNS depressants, narcotic analgesics, cannabis, or no drugs were analyzed using multinomial logistic regression. RESULTS: All drug categories were significantly associated with impaired performance. On the HGN, users of CNS depressants were significantly more likely to experience lack of smooth pursuit and distinct nystagmus at maximum deviation compared to non-drug users. On the OLS, users of all drug classes were significantly more likely to sway while balancing and use their arms to maintain balance but significantly less likely to hop compared to drug-free cases. Users of CNS depressants, CNS stimulants, and narcotic analgesics were significantly more likely to put their raised foot down during the test. On the WAT, users of CNS depressants, CNS stimulants, and narcotic analgesics were significantly less likely to keep their balance while listening to test instructions compared to those who had not used drugs. Users of CNS depressants were less likely to touch heel-to-toe while walking, whereas individuals who had used narcotic analgesics were less likely to take the correct number of steps. CONCLUSIONS: These findings provide support for the use of the SFST as a screening tool for law enforcement to identify impairment in persons who have used CNS stimulants, CNS depressants, cannabis, or narcotic analgesics.

An evaluation of immediate roadside prohibitions for drinking drivers in British Columbia: findings from roadside surveys.

OBJECTIVE: The purpose was to determine the impact of new immediate roadside prohibitions (IRPs) for drinking drivers introduced in British Columbia in September 2010 as assessed by random roadside surveys of alcohol and drug use among nighttime drivers. METHODS: Two roadside surveys were conducted prior to and following the introduction of IRPs. Drivers were randomly selected from the traffic stream in 5 cities and asked to provide a breath sample to determine alcohol content and a sample of oral fluid to be tested for the presence of psychoactive drugs. The survey was conducted between the hours of 9:00 p.m. and 3:00 a.m. on Wednesday through Saturday nights in June 2010 and again in June 2012. RESULTS: Driving after drinking decreased significantly following the introduction of IRPs. In particular, the percentage of drivers with blood alcohol concentrations (BACs) over 80 mg/dL decreased by 59 percent; drivers with BACs of at least 50 mg/dL decreased by 44 percent. The decreases in drinking and driving were not restricted to specific subgroups of drivers but were universal across age groups, sex, and communities. The results also revealed a changing pattern of drinking of driving. For example, the typical pattern of increased drinking and driving on weekend nights was not observed and the prevalence of drinking drivers on the road during late night hours was less than half that found in 2010. The prevalence of drug use by drivers in 2012 did not change from the levels reported in 2010. CONCLUSIONS: The IRP program combined immediate short-term roadside suspensions with vehicle impoundment and monetary penalties to enhance the swiftness, certainty, and perceived severity of sanctions for drinking and driving. The introduction of these measures was associated with a substantial reduction in the prevalence of driving with a BAC over 50 mg/dL and driving with a BAC over 80 mg/dL.

Simplifying the process for identifying drug combinations by drug recognition experts.

OBJECTIVE: The purpose of this study is to statistically identify the set of drug-related cues from Drug Evaluation and Classification (DEC) evaluations that significantly predict the categories of drugs used by suspected drug-impaired drivers. METHODS: Data from 819 completed Canadian DEC evaluations of combinations of central nervous system (CNS) stimulants with cannabis, CNS stimulants with narcotic analgesics, cannabis with alcohol, and no-drug cases were analyzed using a multinomial logistic regression procedure. RESULTS: Eleven clinical indicators from the DEC evaluations significantly enhanced the prediction of drugs used by suspected drug-impaired drivers, including condition of the eyes, lack of convergence, rebound dilation, reaction to light, mean pulse rate, presence of visible injection sites, performance on the Horizontal Gaze Nystagmus Test, pupil size in darkness, performance on the One-Leg Stand Test, muscle tone, and performance on the Walk-and-Turn Test. CONCLUSIONS: The findings from this study will facilitate the process of identifying the correct categories of drugs ingested by suspected drug-impaired drivers by focusing on critical signs and symptoms of drug influence. This work will have direct and immediate relevance to the training of drug recognition experts (DREs) by providing the foundation for an innovative, statistically based approach to drug classification decisions by DREs. This research will also facilitate the enforcement of drug-impaired driving laws in Canada to help make Canadian roadways safer for all.

A roadside survey of alcohol and drug use among drivers in British Columbia.

OBJECTIVE: The purpose was to determine the prevalence of alcohol and drug use among a random sample of nighttime drivers. METHODS: Drivers were randomly selected from the traffic stream in three cities in British Columbia and asked to provide a breath sample to determine alcohol content and a sample of oral fluid to be tested for the presence of psychoactive drugs. The survey was conducted between the hours of 9:00 p.m. and 03:00 a.m. on Wednesday through Saturday nights in June 2008. RESULTS: Of the 1533 vehicles selected, 89 percent of drivers provided a breath sample and 78 percent provided a sample of oral fluid. Key findings include: 10.4 percent of drivers tested positive for drug use. 8.1 percent of drivers had been drinking. 15.5 percent of drivers tested positive for alcohol, drugs, or both. Cannabis and cocaine were the drugs most frequently detected in drivers. Alcohol use among drivers was most common on weekends and during late-night hours; drug use was more evenly distributed across all survey nights and times. Alcohol use was most common among drivers aged 19 to 24 and 25 to 34; drug use was more evenly distributed across all age groups. Though driving after drinking has decreased substantially since previous surveys, the number of drivers with elevated alcohol levels (over 80 mg/dL) was higher than in the past. CONCLUSIONS: The finding that drug use is more common than alcohol use among drivers highlights the need for a unique and separate societal response to the use of drugs by drivers commensurate with the extent of safety risks posed to road users. The observed differences between driving after drug use and driving after drinking have implications for enforcement and prevention.

A meta-analytic review of school-based prevention for cannabis use.

This investigation used meta-analytic techniques to evaluate the effectiveness of school-based prevention programming in reducing cannabis use among youth aged 12 to 19. It summarized the results from 15 studies published in peer-reviewed journals since 1999 and identified features that influenced program effectiveness. The results from the set of 15 studies indicated that these school-based programs had a positive impact on reducing students' cannabis use (d = 0.58, CI: 0.55, 0.62) compared to control conditions. Findings revealed that programs incorporating elements of several prevention models were significantly more effective than were those based on only a social influence model. Programs that were longer in duration (≥15 sessions) and facilitated by individuals other than teachers in an interactive manner also yielded stronger effects. The results also suggested that programs targeting high school students were more effective than were those aimed at middle-school students. Implications for school-based prevention programming are discussed.

Toward a more parsimonious approach to drug recognition expert evaluations.

OBJECTIVE: The purpose of this study is to statistically identify the set of drug-related cues from Drug Evaluation and Classification (DEC) evaluations that significantly predict the substance used by suspected drug-impaired drivers. METHODS: Data from 742 completed Canadian DEC evaluations of central nervous system (CNS) stimulant, narcotic analgesic, and cannabis cases were analyzed using a multinomial logistic regression procedure. RESULTS: Nine clinical indicators from the DEC evaluations significantly enhanced the prediction of drug category, including pulse rate, condition of the eyes and eyelids, lack of convergence, hippus, reaction to light, rebound dilation, systolic blood pressure, and the presence of injection sites. CONCLUSIONS: The findings from this study will facilitate the process of identifying the correct category of drug ingested by focusing on critical signs and symptoms of drug influence. This work will have direct and immediate relevance to the training of drug recognition experts (DREs) by providing the foundation for an innovative, statistically based approach to drug classification decisions by DREs.

Evaluation of the Drug Evaluation and Classification program: a critical review of the evidence.

OBJECTIVE: A critical review of the existing evaluation studies on the Drug Evaluation and Classification (DEC) program was conducted to determine the validity and accuracy of the technique for identifying drivers under the influence of drugs. METHODS: Studies were divided into two categories--laboratory studies and field (i.e., enforcement) studies. A classification process was devised using common criteria based on the toxicology findings (i.e., drug positive or drug negative) and the opinion of the police officer who assessed the driver (i.e., drug positive or drug negative). A series of standard measures (Sensitivity, Specificity, False Alarm Rate, Miss Rate, Corroboration, and Accuracy) were calculated for each to assess the effectiveness of the DEC program. RESULTS: Laboratory studies do not provide overwhelming support for the accuracy with which officers trained in the DEC program can detect and identify the particular class(es) of drug involved based on psychophysical assessment alone. The detection and identification of the relatively low levels of drugs administered were typically better than chance but many cases were missed. The fact that some drugs were detected with greater accuracy than others suggests that the effects of these substances were more prominently manifested in the symptomology assessed by the DEC procedure. Although field enforcement studies are not as scientifically rigorous as laboratory studies, DEC assessments in an enforcement context have the benefit of information obtained from the arresting officer and from interviews with the suspect. In addition, the drug doses consumed by users are typically much higher than those permitted in controlled laboratory studies. In general, officers trained in the DEC program are able to identify persons under the influence of drugs and to specify the drug class responsible with a degree of accuracy that not only exceeds chance, but in some cases reaches a very high level. CONCLUSIONS: There remains room for improvement in the DEC program. As further research becomes available, either from laboratory or field investigations or both, it needs to be incorporated into the program to enhance its validity and accuracy.

Driving after drinking in Canada: findings from the Canadian Addiction Survey.

BACKGROUND: Despite substantial decreases in the magnitude of the alcohol-crash problem over the past 25 years, many Canadians continue to drive under the influence of alcohol, causing thousands of serious injuries and deaths every year. METHODS: Data from the 2004 Canadian Addiction Survey (CAS) were used to determine the prevalence of self-reported driving after drinking and the characteristics of those who engage in the behaviour. RESULTS: Overall, 11.6% of licensed drivers in Canada reported operating a vehicle within an hour of consuming two or more drinks containing alcohol. Less than 5% of licensed drivers accounted for 86% of the more than 20 million (estimated) past-year drinking and driving occurrences. Drinking Drivers reported more extensive and problematic use of alcohol, and were more likely to report illegal drug use relative to Non-drinking Drivers. CONCLUSION: Driving after drinking remains a common behaviour among Canadian drivers. Those who persist in driving after drinking can be distinguished from other drivers on the basis of their greater use of alcohol and drugs. Those who drive after drinking frequently consume even greater quantities of alcohol on more frequent occasions and are more likely to experience problems as a result of their drinking. These findings suggest that countermeasure efforts need to be continued on all levels and expanded to specifically target high-risk heavy drinkers.

Sleepiness among night-time drivers: relationship to blood alcohol concentration and other factors.

OBJECTIVE: The study aimed to explore the distribution and correlates of subjective sleepiness among the general night-time driving population. METHODS: The survey took place in three British Columbia communities in June 2003 between 21:00 hours to 03:00 hours. Sites and vehicles were selected randomly. Surveyors obtained information on several demographic and situational variables including self-assessed degree of sleepiness and self-reported hours asleep and awake, as well as an objective measure of blood alcohol concentration obtained from a hand-held breath-testing device. RESULTS: The total compliance rate among intercepted drivers was 85%. Among the 2335 drivers responding to the questionnaire, 68.4% indicated that they were wide awake, 27.6% were somewhat sleepy, and 4.1% were very sleepy. Logistic regression quantified the independent contributions of the various factors to subjective sleepiness. Male drivers with positive blood alcohol concentrations under 50 mg% were more likely to report feeling sleepy than those with either higher or with zero blood alcohol concentration. Greater relative risk of sleepiness was also associated with being female, being under age 55, and advanced hour of night. Driving with passengers of the same gender was associated with lower reported sleepiness. CONCLUSIONS: A substantial proportion of night-time drivers are driving while sleepy, especially at late night and early morning hours. The combination of alcohol and sleepiness compounds impairment in experimental studies and deserves greater attention in crash risk studies and as a topic for public education and awareness.

Drinking on campus: self-reports and breath tests.

OBJECTIVE: Concern about excessive alcohol consumption by college students has been raised by surveys indicating that more than 40% of students are "heavy" drinkers. This definition is based on students' reports of consuming five or more drinks (four or more for women) on an occasion sometime during the past 2 weeks. The present survey examines the degree to which this 2-week 5+/4+ drink criterion characterizes a student's pattern of alcohol use, and whether a 5+/4+ criterion for a drinking occasion is a valid indicator of high blood alcohol concentration (BAC). METHOD: Students (N = 856, 70% male) were interviewed as they returned home between 10 PM and 3 AM. Students reported their drinking of the past 2 weeks and of the night they were interviewed, then provided breath samples to determine their BAC. RESULTS: Among the students in the sample classified as "heavy" drinkers on the basis of self-reports, 49% had zero BAC on the night they were interviewed. Those who reported consuming 5+/4+ drinks the evening of the interview had a mean BAC <0.08%. The distribution of BACs in the entire sample showed 74.4% of students had a BAC of zero and 11.8% had a BAC <0.05%. Very high BACs (i.e., > or =0.15%) were rare (1.3%). CONCLUSIONS: Self-reports of consuming 5+/4+ drinks on at least one occasion during the previous 2 weeks did not reliably identify a pattern of heavy drinking. Moreover, reports of 5+/4+ drinks on an occasion were not necessarily associated with high BACs.