U.S. Alcohol and Drug Crash

Risk Study Maryland Highway Safety Summit

February 25, 2014

Virginia Beach Police Department

Sgt. Scott Wichtendahl

Pacific Institute for Research and Evaluation

John Lacey

Sponsors

NHTSA

NIAAA

Project Goals

• Conduct a case-control study to assess

the crash risk presented by:

– alcohol-positive,

– drug-positive, and

– alcohol-plus-drug-positive drivers.

Site Selection

• Virginia Beach, Virginia

– Required a jurisdiction with a population of

approximately 400,000 to 500,000.

– The area had a sufficient number of crashes

to allow for data analysis.

– Willingness of the police department and

other local agencies (hospitals and medical

examiners) to cooperate with our stringent

research protocol

Research Team

• Data collector (licensed phlebotomist) and a law enforcement

research officer;

• In some instances, an assistant data collector (not a

phlebotomist)

• The police department dispatcher notified the research officer

of all reported crashes, and the team responded to those

crashes.

• The team’s research officer made contact with the on-scene

investigating officer and the driver(s), and then briefly

introduced the data collector to the driver(s).

• The data collector then asked the driver(s) to participate.

Data Collectors with Equipment

Research Officer

Sample Weekly Schedule

S M T W T F S

Shift 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3

Team 1 X X X X

Team 2 X X X X

Team 3 X X X X

Team 4 X X X X

Team 5 X X X X

Team 6 X X X X

Team 7 X X X X

Shift 1: 6:00 a.m. – 4:00 p.m.

Shift 2: 2:00 p.m. – 12:00 a.m.

Shift 3: 10:00 p.m. – 8:00 a.m.

Example of a Single-Vehicle Crash

Data Collector Administering PBT

Test

Basic Data Collection Procedure

• Observational data:

– While the officer was speaking to the driver(s), the data collector

recorded observable information about the driver and vehicle

• type of vehicle, number of passengers, seat belt usage, gender of

driver, and likely age range of driver

• First PAS reading:

– If the driver agreed to speak to the data collector, the data

collector obtained an initial passive alcohol sensor (PAS) reading

• Consent for interview:

– Data collector explained the purpose of the interview and that it

was voluntary and confidential.

– Obtained verbal consent for continuing with the interview.

– If driver declined, counted as a refusal but the data collector

asked for a breath sample.

Data Collector Taking Initial

Observational Notes

• Financial incentives:

– Data collector offered incentives for oral and blood sample,

and for completing an Alcohol Use Disorder (AUD) and

Drug Use Disorder screening instrument.

• Survey interview questions:

– Survey included questions regarding general drinking

behavior and driving patterns.

• Second PAS reading:

– Data collector obtained a second PAS reading.

Basic Data Collection Procedure (continued)

Data Collector Taking PAS Reading

Basic Data Collection Procedure (continued)

• Breath test:

– Intoxilyzer PA-400TM, a handheld preliminary breath test

(PBT) device manufactured by CMI, Inc.

– PBT did not display result, stored the result in memory.

• Oral fluid test:

– The Quantisal™ (manufactured by Immunalysis

Corporation) oral fluid collection device was used to obtain

samples.

– Subject placed the oral fluid collection swab in mouth for

approximately 3 to 5 minutes until an indicator changed color

indicating approximately 1 mL of saliva had been collected.

Data Collector Administering PBT

Test

Data Collector Administering

Oral Fluid Device

Data Collector Administering Oral Fluid

Device and Drug Questionnaire

Basic Data Collection Procedure (continued)

• AUD and DUD questions: – Self-administered paper-and-pencil AUD screening

instrument and drug use disorder (DUD) completed while the oral fluid swab was in the subject’s mouth.

• Payment: – Subjects were paid $10 for an oral fluid sample and $5 for

completion of the AUD/DUD questionnaire.

• Blood sample: – If the driver consented, the data collector (a certified

phlebotomist) drew blood according to the Occupational Safety and Health Administration (OSHA) standards.

– Subjects were given a $50 money order for the blood sample.

• Completion

Participant having blood drawn

Basic Data Collection Procedure (continued)

• Impaired driver protocol:

– If driver suspected of being impaired, the data collector

obtained a sample of the driver’s breath using a PBT that

displayed the result.

– If the driver had a BAC of .05 grams per deciliter (g/dL) or

higher, the data collector ensured he or she got home

safely by offering several options.

– These options included, but were not limited to – • calling a taxi,

• calling a sober friend/relative to pick up the driver, and

• calling a tow truck to take the driver and vehicle home.

Drivers Injured, Died, or Hit-and-Run

• To have as complete information on crash risk

as possible, we also wanted data from crash-

involved drivers who were injured or died, and

were transported to the hospital or morgue, or

arrested (for DWI or another offense), or hit-and-

run drivers.

• We developed protocols for data collection in

each of these situations.

Protocol for Injured, Fatal and

Hit-and-Run Drivers • If driver is transported to hospital:

‒ Obtain EMS trip report,

‒ Gather data from subject at the hospital,

‒ If no direct contact with driver, use hospital blood sample,

‒ have an RA conduct follow-up interviews, if necessary.

• If driver fatally injured ‒ Followed up with Medical Examiner to obtain blood

results.

• Attempt to identify hit-and-runs ‒ If found within 3 hours, would attempt to recruit

participation.

Data Collection for Control

Drivers

• Control drivers were randomly selected from – traffic stream one week later,

– at the same time of day,

– at the same location, and

– in the same direction of travel as each crash-involved driver.

• Controls served as comparisons to the crash-involved drivers to be able to examine the risk of being in a crash associated with alcohol or drugs.

• Two control drivers were interviewed for each crash-involved driver.

Drug Analysis

• Drugs tested by bioassay and self-report represented a

list of over-the-counter, prescriptions, and illegal drugs

that have the potential to impair driving performance.

• Oral fluid and blood samples were screened and

confirmed for drugs using enzyme-linked

immunosorbent assay (ELISA) micro-plate technology.

• Confirmation was performed using Gas

Chromatography-Mass Spectromony (GC/MS) or

Liquid Chromatography-Mass Spectrometry

(LC/MS/MS) technology.

Drug class

Minimum

concentration

oral fluid (ng/ml)

Minimum

concentration

blood (ng/ml) Self-report item

Screen Confirm Screen Confirm

Cocaine (Cocaine, benzoylecgonine) 20 8 25 10 Cocaine (e.g., crack or coke)

Opiates (6-AM, codeine, morphine, hydrocodone,

hydromorphone) 40 10 25 10

Heroin Morphine or Codeine (e.g.,

Tylenol® with codeine)

Amphetamine/Methamphetamine

(MDMA, MDA, MDEA, Ephedrine,

Pseudoephedrine)

50

50

50

20

20 10

Amphetamine or Methamphetamine (e.g.,

speed, crank, crystal meth)

Cannabinoids (THC, THC-COOH[THCA]) 4 2 10 1 Marijuana (e.g., pot, hash, weed)

Phencyclidine 10 10 10 10 PCP (e.g., angel dust)

Benzodiazepines (oxazepam, nordiazepam,

bromazepam, flurazepam, flunitrazepam, lorazepam,

chlordiazepoxide, temazepam, diazepam,

clonazepam, alprazolam, triazolam, midazolam,

nitrazepam)

20 10 20 10 Benzodiazepines (e.g., Valium® or

tranquilizers)

Barbiturates (Phenobarbital, pentobarb, secobarbital,

butalbital) 50 50 500 500 Barbiturates (e.g., phenobarbital)

Methadone 50 25 50 10 Methadone

Ethyl alcohol .02% .02% .02% .02% Alcohol

Oxycodone (Percocet®) 25 10 25 10

Prescription pain killers (e.g., Percocet®,

OxyContin®, oxycodone, Demerol®,

Darvon®)

Propoxyphene (Darvon®) 10 10 10 10

Tramadol (Ultram®) 50 25 50 10

Carisoprodol (Soma®) 100 50 500 500

Meperidine (Demerol®)

Sertraline (Zoloft®) 50 25 50 10 Anti-depressants (e.g., Prozac®, Zoloft®)

Fluoxetine (Prozac®) 50 25 50 10

Tricyclic antidepressants (amitryptiline, nortriptyline) 25 25 25 10

Zolpidem (Ambien®) 10 10 10 10 Ambien® or other sleep aids

Methylphenidate (Ritalin®) 10 10 10 10 ADHD medications (e.g., Ritalin®,

Adderall®, Concerta®)

Dextromethorphan 50 20 50 20 Cough medicines (e.g., Robitussin®, Vicks

44®, etc.)

Ketamine 10 10 10 10 Ketamine / Special K

Sample

• Drivers ineligible for the study included:

– Drivers younger than 16 years of age

– Drivers of commercial vehicles

– Extremely impaired drivers

– Drivers who did not speak English

Types of Crashes

Number of

Crashes

Viable crashes responded to 2,682

Property damage only 1,781

Injury 886

Fatal 15

Reported here are the numbers of actual crashes that our

survey personnel responded to.

Results – Viable Drivers

Crash Control

Viable Drivers 5,375 7,415

Eligible Drivers 3,887 7,397

Agreed to Participate 3,682 (94.7%) 7,176 (97.0%)

Breath sample 3,393 (87.3%) 7,079 (95.7%)

Oral Fluid or Blood 3,196 (82.2%) 6,935 (93.8%)

Special Case Drivers

Transported to Hospital 729

Eligible 393

Participated 362 (90.8%)

Drivers Arrested 205

Eligible 120

Participated 109 (90.8%)

Hit and Run Drivers 84

Caught 42

Eligible 27

Participated 24 (88.9%)

Results – Viable Crashes

• 2,682 Usable Crashes

– 33.6% injury or fatality (901)

• Injury 886

• Fatality 15

– 66.4% property damage (1,781)

Impaired Drivers and Refusal

Conversions

Crash Control

Refusal Conversion Attempted 46 110

Refusal Conversion Completed 11 (23.9%) 80 (72.7%)

Impaired Driver Protocol 21 30

Calculation Approach

• Univariate and multivariate analyses were

conducted to estimate crash risk

attributable to:

– Alcohol

– Individual drugs

– Drug classes (e.g., marijuana, stimulants,

depressants, etc.)

– Drug categories (i.e., illegal drugs versus

medications)

Preliminary Results

Alcohol Crash Risk Results

0

5

10

15

20

25

30

35

40

Re

lative

Ris

k (

Rela

tive to B

AC

= 0

.00)

BAC

All Driver Breath Samples Drug Negative Drivers Blomberg et al

BAC Relative Risk (Adjusted for Age and Gender)

Relationship of Driver BAC to Illegal Drug

Use

BAC

Any Illegal

Drug

OR %

=>.12 4.05 33.3

=>.08<.01

2

3.29 27.4

=>.05<.08 3.27 28.1

>.00<.05 2.96 25.8

=00 ref. 10.5

Voas , R.B., Lacey, J.H., Scherer, M., Jones, K., & Compton, R. (2012, available

online). Drinking drivers and drug use on weekend nights in the United States. Drug

and Alcohol Dependence. doi:http://dx.doi.org/10.1016/j.drugalcdep.2012.11.007

Preliminary Drug Results

• Raw Summary drug prevalence estimates

for cases and controls

Percent Positive by Drug

Classes (Oral Fluid)

Drug Class

Crash

N %

Control

N %

P

Value

Antidepressants 21 0.7% 50 0.8% 0.50

Marijuana 190 6.1% 320 5.2% 0.05

Narcotic-Analgesics 55 1.8% 125 2.0% 0.42

Sedatives 45 1.5% 92 1.5% 0.90

Stimulants 80 2.6% 158 2.6% 0.93

Other 12 0.4% 12 0.2% 0.08

More than 1 Class 92 3.0% 132 2.1% 0.01

Overall Drug Positive 495 16.0% 889 14.4% 0.04

Negative 2,600 84.0% 5,301 85.6% 0.04

All 3,095 100.0% 6,190 100.0%

Preliminary Results

Oral Fluid and Blood Samples: Drug Type

Distribution

Oral Fluid Blood

Crashes Controls Crashes Controls

N % N % p-value N % N % p-value

Illegal 322 10.4 546 8.8 0.01 59 10.0 109 9.3 0.61

Other 173 5.6 343 5.5 0.92 51 8.7 81 6.9 0.18

Neg. 2,600 84.0 5,301 85.6 0.04 478 81.3 986 83.8 0.18

All 3,095 100 6,190 100 588 100 1,176 100

Contact Information

John H. Lacey Pacific Institute for Research & Evaluation (PIRE)

11720 Beltsville Dr., Ste. 900

Calverton, MD 20705

Ph: 301-755-2779

Fax: 301-755-2808

Email: lacey@pire.org

Website: www.pire.org