Testing reckless drivers for cocaine and marijuana

Drugged driving among U.S. adolescents, 2016-2019, USA

INTRODUCTION

Drugged driving, the operation of a vehicle under the influence of any illegal drugs and alcohol, is a growing problem, but remains understudied among adolescents. The purpose of this article is to estimate past-year driving under the influence of alcohol, marijuana, and other drugs among a large sample of U.S. adolescents and potential associations (e.g., age, race, metropolitan status, sex).

DESIGN

A cross-sectional secondary data analysis of the 2016-2019 National Survey on Drug Use and Health among 17,520 adolescents ages 16-17-years old was conducted. Weighted logistic regression models were built to determine potential associations to drugged driving.

RESULTS

An estimated 2.00% of adolescents drove under the influence of alcohol in the past year, 5.65% drove under the influence of marijuana in the past year, and an estimated 0.48% drove under the influence of other drugs other than marijuana in the past year. Differences were based on race, past-year drug use, and county status.

CONCLUSIONS

Drugged driving is a growing problem among adolescents and interventions are greatly needed to mitigate these behaviors among youth.

The Epidemiology of Cocaine Use Among Hispanic Individuals: Findings From the 2015-2018 National Survey of Drug Use and Health

Cocaine use disproportionately affects several social groups, including ethnic and sexual minorities. The present study sought to identify the epidemiology of cocaine use among a national sample of Hispanic young adults using pooled data from the 2015-2018 National Survey of Drug Use and Health. Weighted analyses were used to identify correlates to past-year cocaine use. Results revealed that 4.11% (n = 729) of individuals used cocaine in the past year. Individuals who identified as gay/lesbian or bisexual, who drove under the influence of alcohol in the past year, and who reported prior drug use were at risk of cocaine use. Of concern, nearly 10% of gay/lesbian Hispanic individuals report having used cocaine in the past year. Furthermore, cocaine use was associated with other risky behaviors; 41.1% of LSD (Lysergic acid diethylamide) users also reported cocaine use, and 18.2% of cocaine users reported having driven under the influence of alcohol within the past year. Findings from the present study may inform harm reduction efforts and health prevention messages.

Driving Under the Influence of Cannabis: A Framework for Future Policy

Marijuana is the most widely consumed illicit substance in the United States, and an increasing number of states have legalized it for both medicinal and recreational purposes. As it becomes more readily available, there will be a concurrent rise in the number of users and, consequently, the number of motor vehicle operators driving under the influence. This article examines the cognitive and psychomotor effects of cannabis, as well as current policy concerning driving under the influence of drugs. The authors performed a MEDLINE search on the epidemiology of cannabis use, its cognitive and psychomotor effects, and policies regarding driving under the influence of drugs. Twenty-eight epidemiological studies, 16 acute cognitive and psychomotor studies, 8 chronic cognitive and psychomotor studies, and pertinent state and federal laws and policies were reviewed. These search results revealed that marijuana use is associated with significant cognitive and psychomotor effects. In addition, the legalization of marijuana varies from state to state, as do the laws pertaining to driving under the influence of drugs. Marijuana is a commonly found illicit substance in motor vehicle operators driving under the influence of drugs. Current evidence shows that blood levels of tetrahydrocannabinol do not correlate well with the level of impairment. In addition, although acute infrequent use of cannabis typically leads to cognitive and psychomotor impairment, this is not consistently the case for chronic heavy use. To establish the framework for driving under the influence of cannabis policy, we must review the current published evidence and examine existing policy at state and federal levels.

Rapid Assessment of Drugs of Abuse

Laboratory testing for drugs of abuse has become standard practice in many settings both forensic and clinical. Urine is the predominant specimen, but other specimens are possible including hair, nails, sweat, and oral fluid. Point-of-care test kits provide for rapid analysis at the site where specimens are collected allowing for immediate action on the results. POCT is based on immunochromatography where the drug in the patient's sample competes with drug and antibody conjugates in the test to develop or block the development of a colored line. Most POCTs are visually interpreted in a few minutes. The potential for false positives is possible due to drug cross-reactivity with the antibodies in the test. False negatives are also possible due to dilution of the sample and the potential for adulteration or sample substitution by the patient. POCT shows more variability than central laboratory testing because of the variety of operators involved in the testing process, but POCT has good agreement for most tests with mass spectrometry provided comparable cutoffs and cross-reactivity of drugs/metabolites are considered. Validation of the test performance with the intended operators will identify potential interferences and operational issues before implementing the test in routine practice. POCT offers faster turnaround of test results provided the limitations and challenges of the test are considered.

Medical marijuana and driving: a review

Medical marijuana remains a highly debated treatment regimen despite removal of state penalties against care providers prescribing the drug and patients treated with the drug in many areas of the USA. The utility of marijuana in specific medical conditions has been studied at length, but its effects on driving performance and risk of motor vehicle collision remain unclear. As with other medications that affect psychomotor function, the healthcare provider should be informed of the potential risks of driver safety prior to prescribing this psychotropic drug to give appropriate anticipatory guidance for appropriate use. The goal of this narrative review is to assess the current literature regarding marijuana as it relates to driving performance and traffic safety. With a foundation in the pharmacology of cannabinoids, we consider the limitations of testing cannabinoid and metabolite concentration. In addition, we will review studies on driving performance and epidemiological studies implicating marijuana in motor vehicle collisions. The increasing prevalence of medical marijuana laws in the USA suggests that clinicians should be aware of marijuana's influence on public safety. Patients should abstain from driving for 8 h if they achieve a subjective "high" from self-treatment with smoked marijuana and should be aware of the cumulative effects of alcohol and other psychoactive xenobiotics.

Fatal crashes from drivers testing positive for drugs in the U.S., 1993-2010

OBJECTIVE

Illegal drug use is a persistent problem, prescription drug abuse is on the rise, and there is clinical evidence that drug use reduces driving performance. This study describes trends in characteristics of drivers involved in fatal motor vehicle crashes who test positive for drugs.

METHODS

We used the Fatality Analysis Reporting System-a census of motor vehicle crashes resulting in at least one fatality on U.S. public roads-to investigate suspected drug use for the period 1993-2010.

RESULTS

Drugged drivers who were tested for drug use accounted for 11.4% of all drivers involved in fatal motor vehicle crashes in 2010. Drugged drivers are increasingly likely to be older drivers, and the percentage using multiple drugs increased from 32.6% in 1993 to 45.8% in 2010. About half (52.4%) of all drugged drivers used alcohol, but nearly three-quarters of drivers testing positive for cocaine also used alcohol. Prescription drugs accounted for the highest fraction of drugs used by drugged drivers in fatal crashes in 2010 (46.5%), with much of the increase in prevalence occurring since the mid-2000s.

CONCLUSIONS

The profile of a drugged driver has changed substantially over time. An increasing share of these drivers is now testing positive for prescription drugs, cannabis, and multiple drugs. These findings have implications for developing interventions to address the changing nature of drug use among drivers in the U.S.

Comparing drug detection in oral fluid and blood: data from a national sample of nighttime drivers

OBJECTIVE

The National Roadside Survey is a study undertaken in the United States to determine the prevalence of alcohol and drugs in randomly selected drivers. Following the success of a 2006 pilot study, the 2007 survey incorporated, for the first time, the collection of biological specimens for drug analysis. This article compares the results obtained from blinded analyses of pairs of oral fluid and blood samples obtained from the same subject.

METHODS

During the 2007 survey, more than 7000 nighttime drivers were randomly stopped and surveyed for their self-reported drug use and were requested to donate an oral fluid specimen using the Quantisal (Immunalysis Corporation, Pomona, CA) device and a blood sample. Overall, 5869 oral fluid specimens were collected from nighttime drivers with 3236 corresponding blood samples.

RESULTS

Biological specimens were analyzed for a wide range of drugs. At nighttime, 14.4 percent of the drivers were positive for drugs in oral fluid, with just over half of those having marijuana present (7.6%). Of the 3236 pairs of specimens, 2676 were negative for all drugs, and 326 matched pairs of samples were both positive, out of which 247 (75.8%) were an exact match for all drug classes and 70 (21.5%) were positive for at least one common drug class.

CONCLUSIONS

Oral fluid and blood samples provided very similar information regarding recent drug intake by randomly tested drivers and oral fluid yielded a higher detection rate for one drug (cocaine) than blood. Oral fluid can be considered a reliable alternative to blood as a matrix for drug testing.

Drugged driving: increased traffic risks involving licit and illicit substances

Driving under the influence of drugs poses risks for traffic safety. Most research attention has been focused on the most prevalent drugs of abuse, such as alcohol, illegal drugs, and prescription drugs with high abuse potential. The objectives of this study were to determine the types of drugs used by convicted DUI offenders on the day of their arrest, prevalence of poly-substance use, and offender characteristics associated with different drug use patterns. Data were collected from 6,339 individuals enrolled in the court-mandated Mississippi Alcohol Safety Education Program. After alcohol, cannabis was the most frequently used substance, followed by sedative medications and prescription analgesics. Among poly-substance users, 78.4% reported combining alcohol with other drugs. Findings could be used to inform public education campaigns, law enforcement training, and highway safety policies about the prevalence of combining alcohol with other drugs, as well as how poly-substance use further impairs traffic-related risks.

Drunk versus drugged: how different are the drivers?

BACKGROUND

Driving under the influence (DUI) of drugs is increasing in the U.S., but little is known about the differences based on their patterns of use and abuse of alcohol and other drugs.

METHODS

This paper uses a large dataset to study patients admitted to Texas substance abuse treatment programs with one or more past-year DUI arrests. t-Tests are used for comparisons between normally distributed continuous data and chi square for categorical data.

RESULTS

First-time DUI offenders not only differ from those reporting more than one past-year DUI, but they differ among themselves in terms of demographics, treatment participation, substance use problems, and mental health disorders. Those with primary problems with methamphetamine, crack cocaine, powder cocaine, other opiates, sedatives, and heroin reported more days of problems and more daily use than those with problems with alcohol, while offenders with primary problems with cannabis were less impaired.

CONCLUSIONS

The most impaired clients were less likely to be referred to treatment from the justice system, and the differences in drug and alcohol offenders show the need to tailor approaches with education and treatment programs. More attention should be given to the needs of drivers impaired through use of prescription drugs such as the opiates and sedatives, as well as female drivers, and the role of acculturation should be recognized in programs for Hispanic drivers. In addition, specific programs should be targeted to young cannabis abusers and underage offenders. All first-time DUI arrestees should be assessed for their levels of impairment.

The need for drugged driving per se laws: a commentary

OBJECTIVE

Triggered by the new federal commitment announced by the Office of National Drug Control Policy (ONCDP) to encourage states to enact drugged driving per se laws, this article reviews the reasons to establish such laws and the issues that may arise when trying to enforce them.

METHODS

A review of the state of drunk driving per se laws and their implications for drugged driving is presented, with a review of impaired driving enforcement procedures and drug testing technology.

RESULTS

Currently, enforcement of drugged driving laws is an adjunct to the enforcement of laws regarding alcohol impairment. Drivers are apprehended when showing signs of alcohol intoxication and only in the relatively few cases where the blood alcohol concentration of the arrested driver does not account for the observed behavior is the possibility of drug impairment pursued. In most states, the term impaired driving covers both alcohol and drug impairment; thus, driver conviction records may not distinguish between the two different sources of impairment. As a result, enforcement statistics do not reflect the prevalence of drugged driving.

CONCLUSIONS

Based on the analysis presented, this article recommends a number of steps that can be taken to evaluate current drugged driving enforcement procedures and to move toward the enactment of drug per se laws.

Risky behaviors and depression in conjunction with--or in the absence of--lifetime history of PTSD among sexually abused adolescents

Posttraumatic stress disorder (PTSD) is often considered the primary problematic outcome of child sexual abuse (CSA). However, a number of other, relatively understudied negative sequelae appear to be prevalent as well. Data from 269 adolescents with a CSA history from the National Survey of Adolescents-Replication Study were therefore used to examine the prevalence of risky behaviors (i.e., problematic alcohol and drug use, delinquent behavior) and depression in this sample. The frequencies of these problems in youth with and without a history of PTSD also were examined. Results indicated that risky behaviors and depression were reported as or more frequently than PTSD. Among youth with a history of PTSD, depression and delinquent behavior were more common than among those without a history of PTSD. However, there were no differences between adolescents with and without a history of PTSD in reported problematic substance use. Findings highlight the need for comprehensive trauma-informed interventions for CSA-exposed adolescents.

Marijuana: use among young males and health outcomes

Marijuana is the most commonly used illicit drug by adolescents and young adults, with more males than females reporting marijuana use. The adolescent and young adult years represent a critical period for interventions to prevent marijuana use and abuse. This article reviews relevant literature, including trends in young males' marijuana use and health effects of marijuana use. By most measures, there has been little net change in marijuana use among 12th graders and young adults since the 1990s. Despite males' greater use, little research has examined gender differences in areas such as metabolism of marijuana and long-term impact of marijuana use. In many areas, including dental health, fertility, and respiratory function, research is either sparse or has yielded conflicting results. Similarly, research on marijuana's carcinogenic effects has yielded conflicting results; however, a small but consistent literature indicates that marijuana use is linked to cancers unique to males. A stronger literature has identified an association between marijuana use and psychiatric problems. Clinical and program interventions for adolescents have potential to prevent marijuana use, as well as screen for and treat marijuana abuse. Improved research is needed, such as research with greater consistency in defining levels of use and greater emphasis on gender differences. Such research would help clinical and program interventions focus on those most at risk for adverse outcomes.

Positive urgency predicts illegal drug use and risky sexual behavior

There are several different personality traits that dispose individuals to engage in rash action. One such trait is positive urgency: the tendency to act rashly when experiencing extremely positive affect. This trait may be relevant for college student risky behavior, because it appears that a great deal of college student risky behavior is undertaken during periods of intensely positive mood states. To test this possibility, the authors conducted a longitudinal study designed to predict increases in risky sexual behavior and illegal drug use over the course of the first year of college (n=407). In a well-fitting structural model, positive urgency predicted increases in illegal drug use and risky sexual behavior, even after controlling for time 1 (T1) involvement in both risky behaviors, biological sex, and T1 scores on four other personality dispositions to rash action. The authors discuss the theoretical and practical implications of this finding.

Work-place alcohol and other drug testing: a review of the scientific evidence

In this paper, scientific evidence for alcohol and other drug testing programs is compared to determine whether each approach is justifiable for improving work-place safety. Three types of studies are reviewed: laboratory, epidemiological and evaluation studies. Laboratory studies show that alcohol use decreases psycho-motor performance; however, for other drugs, some drugs deteriorate performance while others have little effect. Epidemiological studies in the work-place have not provided conclusive evidence that a strong causal link exists between either alcohol or other drug use and work-place injuries/accidents. Evaluation studies have not shown that either drug or alcohol testing significantly reduces work injuries/accidents. Other types of scientific evidence provide some justification of alcohol testing, but not for other drug testing. Alcohol use is much more common than other drug use in industrialized countries, suggesting that alcohol may be more related to industrial accidents than other drugs. As well, epidemiological studies suggest that alcohol is a major factor for traffic collisions, but research is inconclusive for other drugs. Finally, alcohol testing is more justifiable than drug testing because the results of alcohol tests closely correlate with psycho-motor performance while drug tests do not.

Repeat DUI offenders who have had a drug diagnosis: are they more prone to traffic crashes and violations?

OBJECTIVE

Study objectives are to test for differences (1) in rates of negative traffic outcomes between DUI offenders who have lifetime drug use disorders (DUD) and those with no lifetime DUD; and (2) by drug class for those with a DUD.

METHODS

The study sample of 379 male and 74 female repeat DUI offenders was interviewed using the Composite International Diagnostic Interview.

RESULTS

Compared to those with an alcohol use disorder (AUD) only, the relative risk of being involved in a vehicular crash was greater for those with a central nervous system (CNS) depressant use disorder. The risk of being convicted of a traffic offense was higher for those with any DUD and for those with a CNS stimulant use disorder. Differences by class of drug used, after adjusting for demographics, were a 47 percent (confidence interval: 6-103%) greater risk of being in a crash with a CNS depressant use disorder and 28 percent (confidence interval: 11-48%) greater risk of a traffic conviction with a stimulant use disorder.

CONCLUSIONS

Results underscore the increased risk of negative traffic outcomes among repeat DUI offenders diagnosed with DUD, particularly CNS depressant disorders, supporting the call to establish policies that include comprehensive evaluation and treatment for this population.

Driving under the influence of cannabis: a 10-year study of age and gender differences in the concentrations of tetrahydrocannabinol in blood

BACKGROUND

Delta(9)-Tetrahydrocannabinol (THC) is the major psychoactive constituent of cannabis and its various preparations. Increasing use of cannabis for recreational purposes has created a problem for road-traffic safety. This paper compares age, gender and the concentrations of THC in blood of individuals apprehended for driving under the influence of drugs (DUID) in Sweden, where a zero-tolerance law operates.

MEASUREMENTS

Specimens of blood or urine were subjected to a broad screening analysis by enzyme immunoassay methods. THC positives were verified by analysis of blood by gas chromatography-mass spectrometry (GC-MS) with a deuterium-labelled internal standard (d(3)-THC). All toxicology results were entered into a database (TOXBASE) along with the age and gender of apprehended drivers.

FINDINGS

Over a 10-year period (1995-2004), between 18% and 30% of all DUID suspects had measurable amounts of THC in their blood (> 0.3 ng/ml) either alone or together with other drugs. The mean age [+/- standard deviation (SD)] of cannabis users was 33 +/- 9.4 years (range 15-66 years), with a strong predominance of men (94%, P < 0.001). The frequency distribution of THC concentrations (n = 8794) was skewed markedly to the right with mean, median and highest values of 2.1 ng/ml, 1.0 ng/ml and 67 ng/ml, respectively. The THC concentration was less than 1.0 ng/ml in 43% of cases and below 2.0 ng/ml in 61% of cases. The age of offenders was not correlated with the concentration of THC in blood (r = -0.027, P > 0.05). THC concentrations in blood were higher when this was the only psychoactive substance present (n = 1276); mean 3.6 ng/ml, median 2.0 ng/ml compared with multi-drug users; mean 1.8 ng/ml, median 1.0 ng/ml (P < 0.001). In cases with THC as the only drug present the concentration was less than 1.0 ng/ml in 26% and below 2.0 ng/ml in 41% of cases. The high prevalence of men, the average age and the concentrations of THC in blood were similar in users of illicit drugs (non-traffic cases).

CONCLUSIONS

The concentration of THC in blood at the time of driving is probably a great deal higher than at the time of sampling (30-90 minutes later). The notion of enacting science-based concentration limits of THC in blood (e.g. 3-5 ng/ml), as discussed in some quarters, would result in many individuals evading prosecution. Zero-tolerance or limit of quantitation laws are a much more pragmatic way to enforce DUID legislation.

Concentrations of cocaine and its major metabolite benzoylecgonine in blood samples from apprehended drivers in Sweden

Cocaine and its major metabolite benzoylecgonine (BZE) were determined in blood samples from people arrested in Sweden for driving under the influence of drugs (DUID) over a 5-year period (2000-2004). Venous blood or urine if available, was subjected to a broad toxicological screening analysis for cannabis, cocaine metabolite, amphetamines, opiates and the major benzodiazepines. Verification and quantitative analysis of cocaine and BZE in blood was done by gas chromatography-mass spectrometry (GC-MS) at limits of quantitation (LOQ) of 0.02mg/L for both substances. Over the study period 26,567 blood samples were analyzed and cocaine and/or BZE were verified in 795 cases (3%). The motorists using cocaine were predominantly men (>96%) with an average age of 28.3+/-7.1 years (+/-standard deviation, S.D.). The concentration of cocaine was below LOQ in 574 cases although BZE was determined at mean, median and highest concentrations of 0.19mg/L, 0.12mg/L and 1.3mg/L, respectively. In 221 cases, cocaine and BZE were together in the blood samples at mean and (median) concentrations of 0.076mg/L (0.05mg/L) and 0.859mg/L (0.70mg/L), respectively. The concentrations of BZE were always higher than the parent drug; mean BZE/cocaine ratio 14.2 (median 10.9) range 1-55. Cocaine and BZE were the only psychoactive substances reported in N=61 cases at mean (median) and highest concentrations of 0.095 (0.07) and 0.5mg/L for cocaine and 1.01 (0.70) and 3.1mg/L for BZE. Typical signs of drug influence noted by the arresting police officers included bloodshot and glossy eyes, agitation, difficulty in sitting still and incoherent speech.

Concentrations of scheduled prescription drugs in blood of impaired drivers: considerations for interpreting the results

We report the concentrations of scheduled prescription drugs in blood samples from people arrested in Sweden for driving under the influence of drugs (DUID). The investigation covered a 2 year period 2004 (N = 7052 cases) and 2005 (N = 7759 cases) and was prompted by recent legislation stipulating zero-concentration limits in blood for controlled substances. However, prescription drugs are exempt from the zero-limit law provided that the medication was being used in accordance with a doctor's prescription. The blood concentrations of various psychoactive substances were compared with the limits of quantitation of the analytic method used and the so-called therapeutic concentration range according to various reference books and tabulations. Diazepam [N = 1950 (26%)] and nordazepam [N = 2168 (28%)] were the therapeutic agents most frequently identified in these forensic blood samples along with other benzodiazepines such as alprazolam [N = 430 (5.6%)], flunitrazepam [N = 308 (4.0%)], and nitrazepam [N = 222 (2.9%)]. The newer hypnotics, exemplified by zolpidem [N = 148 (1.9%)] and zopiclone [N = 111 (1.5%)], were also high on the list of psychoactive substances identified. Interpreting the concentration of a prescription drug in blood in relation to whether the person had taken an overdose or was abusing the substance in question is not always easy. The age, gender, degree of obesity, and ethnicity of the person concerned; the pharmacokinetic profile of the drug; polymorphism of drug-metabolizing enzymes as well as liver and kidney function and blood hematocrit need to be considered. Among preanalytic factors, stability of the drug in blood after sampling, the type of tubes and preservatives used, the dosage form and route of administration deserve consideration. When therapeutic drug monitoring concentrations are compared with forensic toxicology results, then the plasma-to-whole blood distribution ratio of the drug also needs to be considered. In blood samples from DUID suspects, the concentrations of many commonly used sedatives and hypnotics exceeded the accepted therapeutic limits, which gives an indication of the abuse potential of these types of medications.

Prevalence of alcohol and illicit drugs in blood specimens from drivers involved in traffic law offenses. Systematic review of cross-sectional studies

OBJECTIVE

To determine which is the reported prevalence of alcohol and illicit drugs in blood specimens from drivers involved in traffic law offenses worldwide.

METHODS

The search was performed by using several international biomedical databases. In order to reduce publication bias, additional publications were identified using further sources of information. The present review includes cross-sectional studies published between 1990 and 2005 in English, Spanish, German, Portuguese, and Italian. Only studies based on the analysis of blood specimens and chromatographic quantification of drugs were included.

RESULTS

Forty-nine studies fulfilled the inclusion criteria. Eighteen were excluded considering practical reasons regarding limitations for a reliable interpretation of their results. Alcohol appears to be still the predominant substance, with the consideration that among drivers primarily suspected of DUID, cannabinoids are more prevalent. Among the illicit drugs, cannabinoids are the most commonly found substance. Certain trends could be identified, e.g., very low prevalence of cocaine in reports from Nordic countries, a high prevalence of amphetamines between Norwegian and Swedish studies, and low rates of THC among Australian studies.

CONCLUSION

The results of this study should be regarded as an attempt to obtain more reliable data concerning the prevalence of alcohol and illicit drugs among drivers. To obtain a better assessment of the real current role of alcohol and drugs (illicit and medications), it seems strongly necessary to update the case-control study conducted by Borkenstein et al. in 1964, including now blood analyses of the whole spectrum of substances that can impair drivers.

The impact of cannabis on driving

BACKGROUND

Cannabis is known to have detrimental effects on human performance and may also affect driving adversely. However, studies designed to examine this issue have provided equivocal findings. We set up this study to further determine the effect of cannabis on driving.

METHODS

We used a cross-sectional, case-control design with drivers aged 20-49 who were involved in a fatal crash in the United States from 1993 to 2003; drivers were included if they had been tested for the presence of cannabis and had a confirmed blood alcohol concentration of zero. Cases were drivers who had at least one potentially unsafe driving action recorded in relation to the crash (e.g., speeding); controls were drivers who had no such driving action recorded. We calculated the crude and adjusted odds ratios (ORs) of any potentially unsafe driving action in drivers who tested positive for cannabis but negative for alcohol consumption. In computing for the adjusted OR, we controlled for age, sex, and prior driving record.

RESULTS

Five percent of drivers tested positive for cannabis. The crude OR of a potentially unsafe action was 1.39 (99% CI = 1.21-1.59) for drivers who tested positive for cannabis. Even after controlling for age, sex, and prior driving record, the presence of cannabis remained associated with a higher risk of a potentially unsafe driving action (1.29, 99% CI = 1.11-1.50).

CONCLUSION

Cannabis had a negative effect on driving, as would be predicted from human performance studies. This finding supports the need for interventions to decrease the prevalence of driving under the influence of cannabis, and indicates that further studies should be conducted to investigate the dose-response relationship between cannabis and safe driving.

Drunk, drowsy, doped: skiers' and snowboarders' injury risk perceptions regarding alcohol, fatigue and recreational drug use

The objective was to investigate perceptions of snowfield resort visitors about injury risk regarding alcohol, fatigue and recreational drug use. Visitors to a resort village in a large Australian snowfield region completed a brief survey about fatigue, alcohol and recreational drug use and injury risk perception. Participants stated their ability to ski or snowboard and drive safely following a lack of sleep, alcohol and recreational drug use. Intoxicated snowfield resort visitors were compared with non-intoxicated visitors. Safety beliefs across snow sport and transport were compared. Participants reported that they generally slept less than usual and 30% reported both drinking alcohol and using drugs more than usual while visiting the snowfields. Participants perceived driving as a greater injury risk than skiing/snowboarding (p < 0.001). Fatigue was perceived as a relatively weak injury risk factor, particularly whilst skiing and snowboarding. Awareness needs to be raised among snowfield resort visitors about the contribution of alcohol, fatigue and recreational drug use to snow sport and transport-related injury risk.

Preventing cannabis users from driving under the influence of cannabis

Face-to-face, structured interviews were conducted with 320 recent cannabis users in New South Wales, Australia to assess the likely deterrent effects of (a) increasing the certainty of apprehension for driving under the influence of cannabis (DUIC) and (b) doubling the severity of penalties for DUIC. Participants were presented with a drug-driving scenario and asked to indicate their likelihood of driving given that scenario. The perceived risk of apprehension and severity of punishment were manipulated in each scenario to create four different certainty/severity conditions and participants were randomly allocated to one of these four groups. A subsidiary aim was to assess the likely impact of providing factual information about the accident risk associated with DUIC. Recent drug drivers who felt at low risk of accident when DUIC were asked to rate their willingness to drive if convinced that it was dangerous. The results suggested that increasing the certainty but not severity of punishment would produce reductions in cannabis-intoxicated driving among recent cannabis users. Providing factual information about the risks associated with DUIC would appear to have little impact on drug-driving rates among this population.

Declared and undeclared substance use among emergency department patients: a population-based study

AIMS

To estimate both self-reported and corrected prevalences of substance use in a population-based study of general hospital emergency department (ED) patients and predict undeclared use.

DESIGN

A state-wide cross-sectional, two-stage probability sample survey that incorporates toxicological screening.

SETTING

Seven Tennessee EDs in acute care, adult, civilian, non-psychiatric hospitals.

PARTICIPANTS

A total of 1502 Tennessee residents, 18 years of age and older, possessing intact cognition, able to give informed consent and not in police custody. Measurements Prevalence of self-reported current substance use by age, sex and type with correction for under-reporting based on toxicological screening. Covariates in the multivariate analysis of undeclared use were socio-demographics, ED visit circumstances, health-care coverage, prior health status and treatment history and tobacco addiction.

FINDINGS

Declared current use was highest for alcohol (females 26%, males 47%), marijuana (males 11%, females 6%) and benzodiazepines (females 10%, males 7%). After correction for under-reporting, overall use for any of the eight targeted substances rose from 44% to 56% for females and 61% to 69% for males. Largest absolute changes involved opioids, benzodiazepines, marijuana, amphetamines and/or methamphetamine, with little change for alcohol. Patients aged 65 years and older manifested excess undeclared use relative to patients aged 18-24 years, as did patients not reporting tobacco addiction or receiving substance abuse treatment.

CONCLUSION

Adjustment for under-reporting produced minimal change in the estimated prevalence of alcohol use. However, toxicological screening markedly increased estimates of other drug use, especially for the elderly, who may under-report medication use. Screening tests are useful tools for detecting undeclared substance use.

Relapse to driving under the influence (DUI): A review

Driving under the influence (DUI) is a major public health problem. In 2003, there were 17,401 alcohol-related crash fatalities. Although there has been a large decrease in the fatality rates over the past two decades, further progress has stalled in recent years. This plateau in the injury and death rates resulting from impaired driving has been attributed, in part, to the persistent or repeat DUI offender. Broadly defined, repeat offenders are those individuals who, following an initial DUI arrest, relapse to driving under the influence of alcohol and other drugs. In this paper, we first provide a brief overview of several models of DUI relapse. We then review the empirical literature on DUI relapse, the data describing characteristics of first-time and repeat DUI offenders, and, especially, studies that have evaluated the impact of legal sanctions and rehabilitation programs on subsequent DUI behavior. The data reveal that DUI offenders are a heterogeneous group, and that simple models relying on only one or two behavioral domains (e.g., driving characteristics, demographics) to explain DUI relapse are insufficient to account for the DUI behavior of offenders. To advance our understanding of DUI relapse, we argue for development and testing of multifactorial models focusing on the interplay of legal, social and psychological factors that describe and explain relapse among DUI offenders. By recognizing the heterogeneity within the offender population it will be easier for researchers and clinicians to identify subgroups that are at high-risk for relapse and which should be targeted by prevention and intervention programs.

Motor vehicle collision risk and driving under the influence of cannabis: evidence from adolescents in Atlantic Canada

OBJECTIVE

Employing a sample of 6087 senior students in Atlantic Canada, this paper examines the relationship between driving under the influence of cannabis (DUIC) and motor vehicle collision (MVC) risk. A series of models were analyzed adjusting for demographic characteristics, driver experience, and substance use.

METHODS

Participants were drawn from the 2002/2003 Student Drug Use Survey in the Atlantic Provinces, an anonymous cross-sectional survey of adolescent students in the Atlantic provinces of Canada. Logistic regression techniques were employed in the analysis of unadjusted and adjusted models.

RESULTS

Among senior students, the prevalence of DUIC in the past year was 15.1% while the prevalence of MVCs was 8.1%. The predictors of DUIC were gender, driver experience, use of a fake ID, and driving under the influence of alcohol (DUIA). The predictors of MVC were gender, driver experience, DUIC, and DUIA.

CONCLUSIONS

These findings extend our knowledge of DUIC as a socio-legal and public health issue with implications on road safety. Effort must be placed on educating new drivers about cannabis use in the context of driving.

Acute marijuana effects on human risk taking

Previous studies have established a relationship between marijuana use and risky behavior in natural settings. A limited number of laboratory investigations of marijuana effects on human risk taking have been conducted. The present study was designed to examine the acute effects of smoked marijuana on human risk taking, and to identify behavioral mechanisms that may be involved in drug-induced changes in the probability of risky behavior. Using a laboratory measure of risk taking designed to address acute drug effects, 10 adults were administered placebo cigarettes and three doses of active marijuana cigarettes (half placebo and half 1.77%; 1.77%; and 3.58% Delta9-THC) in a within-subject repeated-measures experimental design. The risk-taking task presented subjects with a choice between two response options operationally defined as risky and nonrisky. Data analyses examined cardiovascular and subjective effects, response rates, distribution of choices between the risky and nonrisky option, and first-order transition probabilities of trial-by-trial data. The 3.58% THC dose increased selection of the risky response option, and uniquely shifted response probabilities following both winning and losing outcomes following selection of the risky option. Acute marijuana administration thereby produced measurable changes in risky decision making under laboratory conditions. Consistent with previous risk-taking studies, shifts in trial-by-trial response probabilities at the highest dose suggested a change in sensitivity to both reinforced and losing risky outcomes. Altered sensitivity to consequences may be a mechanism in drug-induced changes in risk taking. Possible neurobiological sites of action related to THC are discussed.

A review of drug use and driving: epidemiology, impairment, risk factors and risk perceptions

The existing literature on the prevalence of drug driving, the effects of drugs on driving performance, risk factors and risk perceptions associated with drug driving was reviewed. The 12-month prevalence of drug driving among the general population is approximately 4%. Drugs are detected commonly among those involved in motor vehicle accidents, with studies reporting up to 25% of accident-involved drivers positive for drugs. Cannabis is generally the most common drug detected in accident-involved drivers, followed by benzodiazepines, cocaine, amphetamines and opioids. Polydrug use is common among accident-involved drivers. Studies of impairment indicate an undeniable association between alcohol and driving impairment. There is also evidence that cannabis and benzodiazepines increase accident risk. The most equivocal evidence surrounds opioids and stimulants. It is apparent that drugs in combination with alcohol, and multiple drugs, present an even greater risk. Demographically, young males are over-represented among drug drivers. Although there is an association between alcohol use problems and drink driving, it is unclear whether such an association exists between drug use problems and drug driving. Evidence surrounding psychosocial factors and driving behaviour is also equivocal at this stage. While most drivers perceive drug driving to be dangerous and unacceptable, there is less concern about impaired driving among drug drivers and drink drivers than from those who have not engaged in impaired driving. Risk perceptions differ according to drug type, with certain drugs (e.g. cannabis) seen as producing less impairment than others (e.g. alcohol). It is concluded that drug driving is a significant problem, both in terms of a general public health issue and as a specific concern for drug users.

Being "at fault" in traffic crashes: does alcohol, cannabis, cocaine, or polydrug abuse make a difference?

OBJECTIVE

To compare associations of alcohol, cannabis, and cocaine abuse and traffic crash risk for "at fault" crashes and all crashes.

DESIGN

A historical cohort study.

SETTING

Toronto, Ontario. Patients or subjects: Subjects beginning treatment at the Centre for Addictions and Mental Health (CAMH) in 1994 for abuse of alcohol, cannabis, cocaine, and all combinations of these substances (n = 590, with 411 drivers). A control group consisted of 518 records from the Ontario registry of registered drivers, frequency matched for age and sex and residence.

INTERVENTIONS

CAMH subjects took part in therapeutic programs. Pre-intervention (11 115 driver-years) and post-intervention intervals (8550 driver-years) were defined and compared.

MAIN OUTCOME MEASURES

Crash and collision rates, adjusted relative risks (ARRs) of crash involvement and of "at fault" crashes were computed using Poisson regression to control for variations in time at risk, age, and sex of participants.

RESULTS

Pre-treatment, significant ARRs of 1.49 to 1.79 for all crashes were found for abusers of cannabis, cocaine, or a combination. ARRs increased by 10%-15% for "at fault" crashes. Post-treatment, all associations were very modest for all abuse types. Only younger and male drivers had a significantly increased risk, which was stronger for "at fault" than for all crashes.

CONCLUSIONS

Abuse of cannabis and cocaine pre-treatment was more strongly related to "at fault" crashes than to all crashes. Interaction between these substances means that the effects of combined abuse cannot be predicted from simple main effects.

A comparison of Caribbean and non-Caribbean clients in a residential addiction treatment facility in Antigua, West Indies

The first 50 Caribbean clients admitted to a private, multicultural, not for profit addiction treatment center in Antigua, West Indies, were compared with the first 100 non-Caribbean clients admitted. There was no significant difference in age, 38 years (18-61 years) versus 40 years (22-63 years), or gender, 74% versus 67% male. Caribbean clients were more likely to be Black, 68% versus 2%, P < .001. Caribbean clients were less likely to have a prior psychiatric diagnosis, 18% versus 43%, P < .01, or to have been in prior treatment program, 22% versus 64%, P < .001. Caribbean and non-Caribbean clients were equally likely to be polydrug users, 48% versus 50%, and to use alcohol as a primary drug, 52% versus 51%. Caribbean clients were more likely to use cocaine, 30% versus 11%, P < .01, and marijuana, 12% versus 0%, P < .001, but less likely to use heroin, 6% versus 30%, P < .001 or pills, 0% versus 8%, P < .05. Caribbean clients were less likely to have elevated MCV, 24% versus 57%, P < .001 or serum transaminases, 23% versus 46%, P < .01. Differences between groups in this multicultural setting warrant further investigation.

Assessing substance abuse treatment need: a statewide hospital emergency department study

STUDY OBJECTIVE

Health care providers in hospital emergency departments rarely take substance abuse histories or assess associated treatment need. This study compares documentation of psychoactive drug-related diagnoses for adult ED patients in medical records with treatment need assessed through self-report, toxicologic screening, and Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), criteria.

METHODS

A statewide, 2-stage, probability sample survey was conducted in 7 Tennessee general hospital EDs from June 1996 to January 1997. Main outcome measures were the prevalence of diagnosed substance abuse problems, positive bioassay results, denied use, and treatment need. Sensitivity and multivariate analyses were conducted by using varied case definitions of treatment need.

RESULTS

Thirty-one percent (95% confidence interval [CI] 27.3% to 34.7%) of screened ED patients (n=1,330) had positive test results for substance use. Their prevalence of denial of use in the 30 days before the survey ranged from 10% for alcohol (95% CI 5.7% to 14.3%) to 100% for phencyclidine. One percent of all ED patients (n=1,502) had a recorded diagnosis of substance abuse. By contrast, as many as 27% (95% CI 23.3% to 31.8%) were assessed as needing substance abuse treatment on the basis of a comprehensive case definition that accounted for denial and positive test results. A sensitivity analysis using other case definitions is also presented. For example, 4% (95% CI 2.8% to 5.3%) of patients met the very strict definition of DSM-IV current drug dependence only. Under the comprehensive case definition, TennCare patients (adjusted odds ratio [OR] 1.63; 95% CI 1.30 to 2.05) and Medicare patients (adjusted OR 2.50; 95% CI 1.34 to 4.65) showed excess treatment need relative to the privately insured. Excess need was also exhibited by patients reporting 1 or more prior ED visits in the past year (adjusted OR 1.62; 95% CI 1.13 to 2.31) and by patients taking 2 or more hours to reach the ED after the onset of injury or illness (adjusted OR 1.54; 95% CI 1.16 to 2.04). Treatment need was inversely associated with age. Irrespective of case definition, less than 10% of ED patients who needed substance abuse treatment were receiving such treatment.

CONCLUSION

EDs can be important venues for detecting persons in need of substance abuse treatment.

Are drunk-driving offenders referred for screening accurately reporting their drug use?

Several studies report that a substantial percentage of offenders arrested for impaired driving test positive for drugs of abuse besides alcohol. Current guidelines recommend screening offenders for both alcohol and other drug use, yet little is known about the accuracy of self-reports of drug use in this population. We compared drug abuse and dependence DSM-III-R diagnoses from an initial, court-ordered screening evaluation of 583 female and 495 male convicted drunk-driving offenders with diagnoses obtained via a voluntary, non-coerced interview 5 years later. At initial screening, fewer than 6% of offenders were diagnosed with drug abuse or dependence. Among offenders who did not receive an initial drug diagnosis, 28% subsequently reported having experienced drug use problems consistent with a retrospective diagnosis of drug abuse or dependence by the age at which they were screened. Half of those with a retrospective diagnosis of drug dependence reported their initial screening responses were "very accurate". We conclude that, although many drunk-driving offenders undergoing screening have diagnosable drug problems, a high proportion under-report their drug use. We suggest that certain modifications to screening procedures, such as urine drug screening, reducing barriers to treatment, and training counselors in motivational interviewing techniques, may increase accurate identification of drug use problems in this population.

Marijuana use among adolescents

More than half of US adolescents will experiment with marijuana. Of those who try marijuana more than once, approximately one third will subsequently use marijuana regularly, although most will have stopped by their late 20s. Although genetic predisposition plays the most important role in determining who will develop dependence, environmental factors influence who will initiate marijuana use. One of the challenges for prevention and treatment programs is that the immediate adverse effects of marijuana use are not extreme, and many adolescents have difficulty in making decisions based on future risks. Therefore, the consequences of leaving school early, having unprotected sex, and driving while intoxicated are often insufficient to deter adolescents from using marijuana. Thus, it is not surprising that current prevention and treatment programs have had limited success in decreasing the rates of initiation and regular use of marijuana among adolescents. However, the accumulation of data about marijuana use in adolescents has the potential to enable the development of more effective prevention and treatment programs.

The relations of trait anxiety, anxiety sensitivity, and sensation seeking to adolescents' motivations for alcohol, cigarette, and marijuana use

The present study investigated relations of anxiety sensitivity and other theoretically relevant personality factors to Copper's [Psychological Assessment 6 (1994) 117.] four categories of substance use motivations as applied to teens' use of alcohol, cigarettes, and marijuana. A sample of 508 adolescents (238 females, 270 males; mean age = 15.1 years) completed the Trait subscale of the State-Trait Anxiety Inventory for Children, the Childhood Anxiety Sensitivity Index (CASI), and the Intensity and Novelty subscales of the Arnett Inventory of Sensation Seeking. Users of each substance also completed the Drinking Motives Questionnaire-Revised (DMQ-R) and/or author-compiled measures for assessing motives for cigarette smoking and marijuana use, respectively. Multiple regression analyses revealed that, in the case of each drug, the block of personality variables predicted "risky" substance use motives (i.e., coping, enhancement, and/or conformity motives) over-and-above demographics. High intensity seeking and low anxiety sensitivity predicted enhancement motives for alcohol use, high anxiety sensitivity predicted conformity motives for alcohol and marijuana use, and high trait anxiety predicted coping motives for alcohol and cigarette use. Moreover, anxiety sensitivity moderated the relation between trait anxiety and coping motives for alcohol and cigarette use: the trait anxiety-coping motives relation was stronger for high, than for low, anxiety sensitive individuals. Implications of the findings for improving substance abuse prevention efforts for youth will be discussed.

Human factors in the causation of road traffic crashes

Road traffic crashes (RTCs) are responsible for a substantial fraction of morbidity and mortality and are responsible for more years of life lost than most of human diseases. In this review, we have tried to delineate behavioral factors that collectively represent the principal cause of three out of five RTCs and contribute to the causation of most of the remaining. Although sharp distinctions are not always possible, a classification of behavioral factors is both necessary and feasible. Thus, behavioral factors can be distinguished as (i) those that reduce capability on a long-term basis (inexperience, aging, disease and disability, alcoholism, drug abuse), (ii) those that reduce capability on a short-term basis (drowsiness, fatigue, acute alcohol intoxication, short term drug effects, binge eating, acute psychological stress, temporary distraction), (iii) those that promote risk taking behavior with long-term impact (overestimation of capabilities, macho attitude, habitual speeding, habitual disregard of traffic regulations, indecent driving behavior, non-use of seat belt or helmet, inappropriate sitting while driving, accident proneness) and (iv) those that promote risk taking behavior with short-term impact (moderate ethanol intake, psychotropic drugs, motor vehicle crime, suicidal behavior, compulsive acts). The classification aims to assist in the conceptualization of the problem that may also contribute to behavior modification-based efforts.

Illicit drugs and driving: prevalence, beliefs and accident involvement among a cohort of current out-of-treatment drug users

Drug-driving behaviour among out-of-treatment dependent drug users has not been investigated while a theoretical perspective on the propensity of certain drug users to drive while impaired has not been suggested. This paper examines illicit drugs and driving behaviour and accident involvement among out-of-treatment current drug users. Psychological evidence of belief-based mechanisms to account for the decision to drive while impaired by drugs are provided. A total of 210 out-of-treatment current drug users were interviewed in a non-clinical setting by privileged access interviewers. Questionnaire measures were: current illicit drug use, severity of dependence, illicit drugs and driving behaviour, impaired and unimpaired accident involvement and beliefs and perceptions about the impairing effects of a number of illicit drugs. Analyses are restricted to participants who reported driving during the previous 12 months (n = 71). Fifty-eight participants (81.7%) reported driving immediately after consuming illicit drugs, primarily heroin and cannabis. Of these 41.4% (n = 24) had at least one road accident as a driver, 15 of whom (62.4%) reported accident involvement following recent drug consumption. Belief-based results showed that participants who reported never driving after using illicit drugs perceived heroin, methadone and alcohol to be greater significance for accident risk and driving skills impairment than other drugs. Those drivers who reported drugs and driving behaviour believed only alcohol to be significantly more impairing than other drugs. Findings indicated that illicit drugs and driving behaviour is common among out-of-treatment drug users. Accident involvement among this cohort is characterised by the previous consumption of illicit substances. Differential beliefs about the effects of drugs on driving performance and accident risk were shown to be dependent upon frequency of drugs and driving behaviour. Results are discussed in terms of experiential factors and consistency theories of attitude formation and change.

Effectiveness of coerced addiction treatment (alternative consequences): a review of the clinical research

Of central importance is that our clinical experience and treatment outcome studies to date strongly suggest that coercion is fundamental to addiction treatment and favorable outcomes from therapeutic interventions. Often the alcoholic/drug abuser must be given an opportunity to feel, face, or experience the "consequences" of their alcohol and drug addiction before the denial of their illness can be penetrated and motivation for treatment to recover from addictive illness can be developed. Continued use of alcohol and drugs is an unhealthy and dangerous state for those who are addicted and for others who are affected by their addictive illnesses. Effective therapeutic interventions and long-term recovery are more likely to succeed if avoiding "alternative consequences" are contingent on continued compliance with addiction treatment by those who suffer from addictive illnesses.

Unsafe motor vehicle practices among substance-using college students

This study examines the relationship between substance use and behaviors that increase the risk for motor vehicle crashes and crash-related injuries. The investigation uses National College Health Risk Behavior Survey data collected in 1995 by the Centers for Disease Control and Prevention. These data are representative of 2- and 4-year undergraduate college students in private and public colleges and universities in the United States. Smokers, episodic heavy drinkers, marijuana users and users of illegal drugs in combination with alcohol were significantly more likely to drive after drinking alcohol and ride with a driver who had been drinking alcohol and significantly less likely to wear safety belts while driving or while riding in a car as a passenger. This study indicates that college students who are substance users are more likely to behave in a manner which increases their risk for motor vehicle crashes and motor vehicle crash injuries.

David R. Boyd lecture in trauma care and emergency medical systems: "The surgical complications of toxins."

Toxins have had major roles in our societies for thousands of years. Interactions between surgeons, both generalists and subspecialists, and those caring for poisoned patients have been extensive throughout history. The advancement of the science of toxicology, the development of regional poison control centers, the development of emergency medicine, and the development of the subspecialty of medical toxicology have led to more appropriate and creative interactions between medical toxicologists, emergency physicians, and surgeons. This article will review the diverse interfaces between the medical toxicologist and the surgeon.

On the high road: driving under the influence of cannabis in Ontario

While cannabis is the most frequently found illegal drug in drivers killed or injured in motor vehicle collisions, little is know about driving under the influence of cannabis (DUIC) in the general population. We report information on the incidence of DUIC in a representative sample of the Ontario adult population. Among all drivers, 1.9% reported DUIC in the previous 12 months. Several factors influenced the likelihood of reported DUIC, including gender, age, marital status and education level. Among cannabis users, DUIC appeared to be a relatively common behaviour; 22.8% reported DUIC, and the probability of the behaviour was significantly influenced by gender and education level. As well, DUIC and drinking-driving were strongly related in this sample. These data underscore the need to obtain more information on this behaviour, including a more complete understanding of any risks involved.

Detecting cocaine and opiates in urine: comparing three commercial assays

Urine screening is a potentially useful tool for detecting drugs of abuse in treatment, criminal justice, and other human service settings. This article examines the relative accuracy and other features of three drug screening assays sold by commercial laboratories: (1) Abbott Diagnostics ADx machine and reagents; (2) ONTRAK, manufactured by Roche Diagnostics; and (3) EZ-SCREEN, manufactured by Environmental Diagnostics. Urine samples (n=345) were collected from indigent men and women in a work and life skills program, and tested for cocaine and opiates with each of the kits. The ADx fluorescent immunoassay was presumed to be the most sensitive and specific screening method, and comparisons with the two visually-determined test kits supported this assumption. Of the two visual test kits, ONTRAK was the more specific assay, and was lower in cost and simplest to perform. Decision makers could employ similar evaluative methods in selecting drug testing materials.

Marijuana and Job Performance: Comparing the Major Streams of Research

Though some estimate that marijuana use has cost U.S. companies billions of dollars in lost productivity, the relationship between use of marijuana and job performance is far from clear. In this paper, I review studies on this topic from four different methodological perspectives and discuss models to account for their apparently contradictory findings. This discussion suggests hypotheses for future research addressing possible reasons for inconsistencies in past findings.

Predicting DUI recidivism: blood alcohol concentration and driver record factors

This study examined the relationship between blood alcohol concentration (BAC) at arrest, driving history and other demographic factors, and the 1-year post-arrest probability of recidivism for drunk driving (DUI) convictees. Complex and simple prediction models were developed. All models found a statistically significant cubic relationship between BAC and recidivism, reflecting a relatively high rate of recidivism at a BAC of 0.00%, decreasing to a minimum at ca 0.09% BAC, then increasing to another relatively high rate at a BAC of ca 0.29%, followed by a decline in recidivism to BAC levels of 0.35% and beyond. High rates of recidivism at high BACs suggest alcohol dependency, while high rates at low BACs suggest the involvement of other impairing substances. The rate of DUI recidivism for offenders who refused alcohol testing was the same as for aggregated BAC-tested offenders who had prior DUIs at the time of the arrest. The probability of DUI recidivism predicted by a simple model using BAC, prior 2-year traffic convictions, and offender level (first or repeat offender) could be used along with other factors by presentence investigators, judges or in administrative settings to determine appropriate sanctions, treatment or other remedial measures. The findings support the notion that first offenders with high BAC levels and prior 2-year traffic convictions are at as high a risk of recidivating as many repeat offenders, and might therefore benefit from similar sanctions and/or remedial treatment. The findings also support viewing DUI arrestees with very low BACs as probable drug users with relatively high probabilities of recidivating.