Substance Use and Driving – The state of knowledge

1. A DRIVING FORCE FOR SAFETY

2. Substance Use and Driving – The state of knowledge Ward Vanlaar Research Associate Traffic Injury Research Foundation Smartrisk Learning Series Teleconference January 29th, 2007 A DRIVING FORCE FOR SAFETY

3. Overview • Drinking and driving • Risks • Epidemiological data • Public perception • Solutions • Driving under the influence of other substances • Risks • Epidemiological data • Public perception • Solutions A DRIVING FORCE FOR SAFETY

4. Drinking and driving: Relative risk of crash A DRIVING FORCE FOR SAFETY

5. Slow but steady progress Many countries including Canada experienced a decline in alcohol-related crashes in the 1980s and 1990s. A DRIVING FORCE FOR SAFETY

6. Persons Killed in alcohol involved Crashes A DRIVING FORCE FOR SAFETY

7. The easy gains? • Many experts agree that these declines can be traced primarily to socially responsible individuals: • they were drinking and driving less often. • they were consuming less alcohol if they did drink and drive. A DRIVING FORCE FOR SAFETY

8. Into the new millennium • Progress basically halted as we entered the new millennium. • Same pattern holds for all the reliable indicators we have. A DRIVING FORCE FOR SAFETY

9. The problem today • Despite progress, the problem persists at unacceptable levels. A DRIVING FORCE FOR SAFETY

10. The problem today Given these statistics, it is not surprising to find that drinking and driving is anything but uncommon. A DRIVING FORCE FOR SAFETY

11. The problem today • We estimate that in the past year there were some 10.2 million trips in Canada during which people drove when they thought they were over the legal limit. A DRIVING FORCE FOR SAFETY

12. Who is the problem ? 92.4% of all those “impaired” driving trips were taken by only 4.4% of all drivers. A DRIVING FORCE FOR SAFETY

13. A major problem • The Hard Core Drinking Driver • The High-BAC Driver • The Repeat Offender • The Persistent Drinking Driver • The Chronic Drunk Driver A DRIVING FORCE FOR SAFETY

14. Profile of the Hard Core • Often drink and drive -- this is frequent and routine behaviour for them. • Usually have consumed large amounts of alcohol -- this is extremely dangerous for them and others. • Many are alcohol dependent. A DRIVING FORCE FOR SAFETY

15. Drinking-driving decreasing or increasing? A DRIVING FORCE FOR SAFETY

16. Drinking-driving decreasing or increasing? A DRIVING FORCE FOR SAFETY

17. How concerned are Canadians? A DRIVING FORCE FOR SAFETY

18. Why are Canadians so concerned? • They think drinking and driving is very common; • They believe drinking and driving comes with the highest possible risk; • Their concern for drinking and driving is further compounded by their belief that drinking-drivers are not concerned about the risks they pose. A DRIVING FORCE FOR SAFETY

19. Solutions • We need measures that will: • Protect the public • Change behaviour A DRIVING FORCE FOR SAFETY

20. Solutions • Many such effective programs have already been introduced in Canada (e.g., ignition interlocks, vehicle impoundment, treatment). A DRIVING FORCE FOR SAFETY

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22. Summary The hard core should be a priority for drinking-driving countermeasures. But by no means should this exclude our focus on “social drinkers” or young drivers. A DRIVING FORCE FOR SAFETY

23. Other substances and driving • Highly controversial and often confusing issue. • Many claims; fewer solid facts. • Near hysteria can surround the issue – societal ambivalence: alcohol (OK); drugs (not OK). • Moral overtones – illegal (bad) versus legal (good) drugs. A DRIVING FORCE FOR SAFETY

24. Drugs and driving – complex issue • Drugs and driving is a much more complex issue than drinking and driving. • Complexities account for shortcomings in knowledge and different interpretations of evidence. • Public’s perceptions, attitudes and behaviour may be influenced by this complicated picture. A DRIVING FORCE FOR SAFETY

25. Why it is so complicated? • Many different drugs; highly complex chemicals. • Different populations of users. • Effects (pharmacodynamics) differ by drug and user. • Testing for presence vastly more complex than testing for alcohol. A DRIVING FORCE FOR SAFETY

26. Five key questions • Do drugs impair skills/abilities needed for safe driving? • Do people actually use these drugs while they are driving? • Are drivers who use them involved in collisions? • Is there evidence that the presence of the drug caused the crash? • How do people perceive the seriousness of drugs and driving? A DRIVING FORCE FOR SAFETY

27. Do drugs impair driving skills? • Yes. Experimental studies show a wide range of drugs impair critical skills and abilities. • Some have a potent impact particularly those with a sedative/hypnotic effect. Some have a moderate effect (cannabis); some are less likely to cause impairment (stimulants). A DRIVING FORCE FOR SAFETY

28. Do people use them and drive? • Yes, but... Data on frequency and quantity of drug use in the driving population are sketchy. • Best estimate is that about 10% of drivers are using impairing drugs. • Marijuana is the most commonly reported/detected and is most commonly used by young males. A DRIVING FORCE FOR SAFETY

29. Do people use them and drive? • 2.4% of drivers in TIRF’s 2005 RSM indicated they had driven within 2 hours of using marijuana or hashish during past 12 months. • Applied to the entire population, this corresponds to about 520,000 Canadians driving after using. • There seems to be an increasing trend. In 2002: 1.5%; in 2004: 2.1%. A DRIVING FORCE FOR SAFETY

30. Characteristics of users • Those who reported using marijuana/hashish were: • more likely to be male (72% versus 55% among non-users) • more likely to live in an urban setting (89% vs. 77%) • less likely to be married (42% vs. 65%) • more likely to have received a traffic ticket in past 12 months (40% vs. 10%) • more likely to have been involved in a traffic collision (15% vs. 10%) A DRIVING FORCE FOR SAFETY

31. Characteristics of users • But…does the use of drugs increase risk taking or are users in general more likely to be risk takers? • A considerable body of evidence shows that unhealthy lifestyle (e.g., smoking) and negative attitude toward health and safety are related to wide range of risky behaviours, including driving. A DRIVING FORCE FOR SAFETY

32. Characteristics of users • In 2005 RSM, users were more likely than non-users to “take a risk when driving just for fun” and “to drive over the posted speed limit”. • Such findings make it difficult to establish a causal link between the impairing effects of cannabis and crash risk. • Perhaps other factors such as willingness to take risk increase the likelihood of crash involvement, rather than the effects of cannabis. A DRIVING FORCE FOR SAFETY

33. Are drivers who use them involved in crashes? • Yes. Overall incidence of drug detections among drivers killed or injured in road crashes is in the 14-17% range. • Most commonly detected substances are: • cannabis (10-11% of cases); • benzodiazepines (5-9% of cases) – class of drugs with hypnotic, anxiolytic, anticonvulsant, amnestic properties. A DRIVING FORCE FOR SAFETY

34. How many crashes are caused by drug impairment? • Unknown, because the evidence of the contribution of drugs to crashes is inconsistent and inconclusive. • When drugs are detected in blood they are frequently found in combination with alcohol (as many as 84% of the cases with some drugs also test positive for alcohol). • Distinguishing between the effects of the drugs and the characteristics of the users (e.g., risk taking among some users; reduced skills in general among elderly) is challenging. A DRIVING FORCE FOR SAFETY

35. Perceived seriousness of problem • Canadians are very concerned about issue of drugs and driving according to TIRF’s 2005 RSM. • 87% perceive young drivers impaired by alcohol or drugs as a serious or extremely serious problem. • 61% perceive older drivers impaired by prescription medication as serious or extremely serious problem. • By comparison, 86% perceive drinking drivers as serious or extremely serious. A DRIVING FORCE FOR SAFETY

36. Perceived seriousness of problem • Evidence suggests a high level of concern among Canadians. • Evidence also suggests that people arenot very good at estimating risk and incidence levels for driving after using drugs. • Public may overestimate risk and incidence and attribute less concern to other important road safety issues (e.g., drinking and driving). • Balanced messages to public are crucial. A DRIVING FORCE FOR SAFETY

37. Summary • Many drugs impair skills and abilities deemed important for the safe operation of a vehicle. • Many of these drugs are used by people when they drive. • Many of these drugs are found in drivers involved in collisions. • The risks (contributory effects) are not well established. • Public may not be able to appreciate problem in proportion to its true dimensions. • On balance the evidence shows that the problem is by no means trivial even though it still is not well understood. A DRIVING FORCE FOR SAFETY

38. Action needs • Continue research to clarify the magnitude and characteristics of the problem (e.g., EU-project DRUID). • There is a need to verify whether young people are “substituting” drugs for alcohol to avoid detection/arrest. • There is a need to study the perception of seriousness in more detail to determine whether Canadians attribute a proper level of concern to this issue. • Continue efforts to produce a reliable chemical test for screening at roadside; cf. ROSITA-project (ROadSIde Testing Assessment; www.rosita.org). A DRIVING FORCE FOR SAFETY

39. Action needs • In absence of reliable chemical roadside test, alternative is to facilitate the collection of evidence of impairment – SFST. • Also need a companion drug evaluation – DRE. A DRIVING FORCE FOR SAFETY

40. www.trafficinjuryresearch.com -TIRF - Traffic Injury Research Foundation A DRIVING FORCE FOR SAFETY