Driving under the influence of prescription opioids among senior highschool students in Atlantic Canada: Prevalence, key correlates, and the role of intentions to use Mark Asbridge, PhD Donald Langille, MD Jennifer Cartwright, MA Department of Community Health and Epidemiology Dalhousie University
6/12/2014 Talk Overview 1. Outline what we currently know about opioids and driving 2. Review the design, methods, and analysis for the current study 3. Describe key findings 4. Discuss the implications of our work to research and policy 2Safety 2012 World Conference
6/12/2014 Opioids Opioids comprise a broad range of natural (derived from the opium poppy) and synthetic compounds such as morphine, codeine and oxycodone that are frequently used for pain relief. Common brands of prescription opioids include Percocet, OxyContin and Tylenol. The rate of official prescription opioid consumption is rising. In the last five years, Canadians have become the second largest per capita consumers of prescription opioids. 3Safety 2012 World Conference
Recreational (non-medical) consumption
6/12/2014 Opioids and Driving 5Safety 2012 World Conference
What we know about driving under the influence of opioids? 66/12/2014
6/12/2014 Opioid consumption and crash risk Epidemiological studies find that recent opioid use the risk of collision The average effect is a doubling of the odds of a crash, whether involving an injury, fatality, or property damage crash There is a dose-response effect, with increasing opioid dose associated with higher likelihood of a road trauma 7Safety 2012 World Conference
6/12/2014 The Current Study 1. What is the prevalence of driving under the influence (DUIO) among senior high school youth in Atlantic Canada? 2. What sociodemographic and psychosocial predictors are associated with DUIO? 3. Is there a relationship between intentions to use opioids, either medically or for recreational reasons, and DUIO? 4. Is DUIO associated with other risky driving behaviours, including driving under the influence of alcohol (DUIA) or cannabis (DUIC), and being a passenger of an impaired driver? 8Safety 2012 World Conference
Data
Sample Two-stage stratified cluster sample of randomly selected classes containing at least 20 students in the surveyed grades within each health region of the three provinces. The sampling frame allowed for approximately proportional representation of each province, within each health region, within each grade (7, 9, 10 or 12); thereafter, the sample was allocated according to school size. All students who participated in the survey needed parental consent to do so, unless they were 19 years of age or older. Participation rates were high, with 90% of students present on the day of survey administration taking part in the SDUSAP.
Dependent Measures Key outcome measure was based on the following question: In the past 12 months, how often have you driven a vehicle within an hour of using a PRESCRIPTION PAIN RELIEF PILL such as Percocet, Percodan, Tylenol #3, Demerol, Oxycontin, or codeine? Dichotomized to yes and no, and only among those students who answered positively to having used pain medications.
Independent Measures A number of control variables include: Gender Family structure Mothers education Socioeconomic status* School grades School decision-making classes General physical health* Sensation seeking* Parental attachment* *Based on existing validated scales
Other Measures Prescription Opioid Use Intentions Medically or Recreationally Other past 12 month risky driving behaviours Driving under the influence of alcohol (DUIA) Driving under the influence of cannabis (DUIC) Being a passenger of a drinking driver Being a passenger of a cannabis driver
Safety 2012 World Conference 6/12/2014 Statistical Analysis 1. Descriptive overview of opioid use and DUIO among senior students in grades 10 and 12 in Atlantic Canada (n=3655) 2. Logistic regression models to examine factors associated with DUIO, including use intentions. 3. Series of logistic regression models to examine the association between other risky driving behaviours and DUIO, stratifying by use intentions For questions 2 and 3, only students who had used opioids in the past 12 months were included in the analyses (n=1136) All analyses employ the survey commands in Stata 13 to adjust for the complex survey design 15
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Table 1. Unweighted N and weighted prevalence estimates for prescription pain medication use among senior high school students in Atlantic Canada (n=3655) Covariates Any use of a prescription pain medication in the past 12 months Medical use of a prescription pain medication in the past 12 months Recreational use of a prescription pain medication in the past 12 months Overall 1136 (32.1) 642 (18.1) 494 (14.0) Gender Female Male 650 (36.0) 486 (28.0) 404 (23.0) 238 (12.8) 246 (13.0) 248 (15.1) Family Structure Two parent family Other 817 (31.4) 319 (34.0) 501 (19.3) 141 (14.7) 316 (12.0) 178 (19.3) Mothers Highest Education Post-secondary High school or less 689 (32.1) 447 (32.1) 408 (18.6) 234 (17.3) 281 (13.5) 213 (14.7) Socioeconomic Status Low SES Average SES High SES 129 (27.4) 622 (32.9) 385 (32.3) 57 (10.7) 344 (18.4) 241 (20.3) 72 (17.1) 278 (14.6) 144 (12.0) School Grades A average B average Less than B average 473 (30.2) 322 (30.4) 341 (37.2) 330 (20.6) 182 (18.3) 130 (13.6) 143 (9.6) 140 (12.1) 211 (23.6) Decision-making classes Yes No 616 (32.7) 520 (31.3) 359 (18.5) 283 (17.5) 257 (14.2) 237 (13.8) General Physical Health Fair/Poor Good/Very Good/Excellent 146 (37.1) 990 (31.5) 60 (13.9) 582 (18.5) 86 (23.2) 408 (13.0) Sensation Seeking Scale (4-16) N (mean) 1136 (11.6) 642 (11.1) 494 (12.2) Parental Attachment Scale (3-15) N (mean) 1136 (11.97) 642 (12.4) 494 (11.3)
DUIO Prevalence The weighted prevalence estimates for driving under the influence of opioids (DUIO) in the past 12 months amongst senior students who have used pain medications was 14%. The rate was significantly higher among recreational users at 19.7%, compared to those using medically at 9.6%.
Table 2. Logistic regression for driving under the influence of opioids (DUIO) among senior high school students in Atlantic Canada who have used pain medications (n=1136) and covariates (Odds Ratios and 95% CI s presented) Unadjusted Adjusted Adjusted w/ intention of opiate use Covariates Socioeconomic Status Low SES Average SES High SES 1.00 1.74 (0.76-4.01) 1.77 (0.76-4.11) 1.00 2.10 (0.92-4.81) 2.22 (0.97-5.12) 1.00 2.25 (0.98-5.16) 2.40 (1.04-5.54)* School Grades Less than B average A average B average 1.00 0.48 (0.27-0.84)* 0.88 (0.43-1.81) 1.00 0.54 (0.26-1.13) 0.97 (0.45-2.07) 1.00 0.58 (0.29-1.17) 1.08 (0.60-2.13) Sensation Seeking Scale 1.21 (1.08-1.37)* 1.17 (1.03-1.33)* 1.16 (1.01-1.33)* Parental Attachment Scale 0.85 (0.79-0.92)* 0.91 (0.84-0.98)* 0.92 (0.85-0.99)* Opiate Medication Use Intention Medical Recreational 1.00 2.32 (1.06-5.07)* --- 1.00 2.01 (1.01-4.12)*
DUIO and other risky driving behaviours
For medical users, DUIO was associated with no other risky driving behaviours
Safety 2012 World Conference 6/12/2014 Summary The prevalence of DUIO among senior students in Atlantic Canada was substantial Rates of DUIO were higher in those students who report higher sensation seeking and, to a lesser extent, those of higher SES Rates of DUIO were lower in students with stronger parental attachment 22
Summary Intentions matter.
Safety 2012 World Conference 6/12/2014 Implications The observed rate of DUIO among young drivers in Atlantic Canada is a concern On the one hand among recreational users. DUIO as part of the risk continuum On the other hand, among medical users Improve knowledge of opioids and driving risk Public awareness Increase education at point of contact with health care professional (physician or pharmacist) 24
6/12/2014 Questions 25 Safety 2012 World Conference