Transcript Drug Driving Enforcement - Druid

Drug Driving Enforcement
Marjan Hagenzieker and Sjoerd Houwing
www.swov.nl
TRB 2012 DRUID session
November 2006
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Partners
KLPD (NL)
DTU (DK)
THL (FI)
SWOV (NL)
UGent (BE)
TØI (NO)
TRB 2012 DRUID session
November 2006
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Introduction
Drugs and driving is a serious road safety problem.
Before 2006 only a few EU member states had specific
legislation for drugs and driving.
Urine screening devices were used to detect the
presence of a specific drug.
Now oral fluid screening devices are the standard. They
were evaluated in the ROSITA 2 project (2003-2005), but
have they improved since then?
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November 2006
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Main objectives
To get more insight in the usability of oral fluid
screening devices
To get more insight in the reliability of oral fluid
screening devices
To get more insight in the cost effectiveness of drug
driving enforcement
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November 2006
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Practical evaluation
• Evaluation of 13 oral fluid screening devices from an
operational police perspective by 10 different police teams
in 6 European countries.
• All devices were tested by each of the 10 police teams.
• Devices were evaluated on 6 items:
• Succesful test performance
• Duration sample collection
• Duration sample analysis
• Hygienic aspects
• Impression reliability
• Simplicity of the test
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Practical evaluation
8 devices have been qualified as promising:
Mavand RapidSTAT
Securetec Drugwipe 5+
Branan Oratect XP
Varian Oralab 6
Innovacon OrALert
Cozart DDS
Dräger Drug Test 5000 Biosensor BIOSENS*
* During specific enforcement activities where a great number of persons should be tested in a limited period of time.
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November 2006
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Promising Oral fluid screening devices
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Analytical evaluation
• Study population consisted of randomly selected drivers from the DRUID
roadside survey, suspected drivers, patients of rehabilitation clinics and treatment
centres, and customers of coffeeshops.
• Devices were evaluated on: sensitivity, specificity, accuracy
Sensitivity 
TP
TP  FN
Specificit y 
TN
TN  FP
Accuracy 
TP  TN
TP  TN  FP  FN
TRB 2012 DRUID session
November 2006
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Analytical evaluation
Desired target value: 80% for sensitivity and specificity
for all substances
Not met by any of the devices!
Substance
Sensitivity Specificity Accuracy
Cannabis
11-59%
90-100%
84-98%
Amphetamines
0-87%
90-100%
84-98%
Cocaine
13-50%
99-100%
86-100%
Opiates
69-90%
81-100%
75-99%
Benzodiazepines
48-67%
94-100%
77-100%
TRB 2012 DRUID session
November 2006
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Analytical evaluation
In practice the police would rather be interested in
the overall sensitivity:
If a driver is positive for a specific drug or
combination of drugs, any positive screening result
is regarded as a true positive result.
TRB 2012 DRUID session
November 2006
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Task 3.2
Overall sensitivity vs. overall specificity
Only DrugTest 5000, RapidSTAT, and Drugwipe 5+
are above the 80% for sensitivity and specificity
TRB 2012 DRUID session
November 2006
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Evaluation preselection test
Evaluation checklist of Clinical Signs of Impairment (CSI)
• Very low correlation between signs and symptoms and actual
presence of drugs. Mainly in high concentrations or very recent use.
• Pupil reaction test was best predicting parameter, esp. for AMP and
THC.
• Sensitivity of the checklist was 32%. For signs and symptoms only
even lower: 13%.
• More experience, better training, and selection of time and locations
with high incidence may improve the results of the CSI.
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November 2006
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Cost-Benefit Analysis
• Societal cost-benefit analysis (CBA)
 Costs of increased enforcement
 Benefits of reduced casualties (valuation of prevented
fatalities/injuries/damage) due to increased enforcement
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Main conclusions CBA #1
An increase of drug driving enforcement should not result
in a decrease of drink driving enforcement
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November 2006
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Main conclusions CBA #2
Oral fluid screening devices that perform above average
have a higher Benefit-Cost ratio than devices that perform
below average
Figure: BC ratios for three quality groups of devices
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November 2006
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Main conclusions CBA #3
Drug driving enforcement is potential beneficial,
particularly for countries that currently have a low
enforcement level
Baseline number of drug tests
per 100.000 inhabitants
Net benefits 50% increase
BC ratio 50% increase
Net benefits tripling
BC ratio tripling
Net benefits 10-fold increase
BC ratio 10-fold increase
Netherlands
Belgium
Finland
6
36
145
5,407,268
19.6
13,220,740
13.74
18,297,599
5.04
11,844,255
8.04
27,232,590
5.09
24,429,424
1.82
438,494
1.27
-1,335,197
0.79
-21,124,469
0.28
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November 2006
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Summary
Eight of the thirteen evaluated devices were evaluated as
promising from an operational police perspective.
None of the promising oral fluid screening devices was
very sensitive for all substances. But the usability of a
device depends on the prevalence of the target
population.
Drug-driving enforcement should not go at cost of alcohol
enforcement.
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November 2006
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Answer to the question
Did oral fluid screening devices improve since the
ROSITA II study?
• From an operational police perspective they did.
• But from an analytical point of view there was hardly
any improvement of performance
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November 2006
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More information
www.druid-project.eu
D3.1.1 Evaluation of oral fluid Screening devices by TISPOL to Harmonise
European police Requirements (ESTHER)
D3.2.1 Protocol of “workshop on drug driving detection by means of oral
fluid screening
D3.2.2 Analytical evaluation of oral fluid screening deivces and preceding
selection procedures
D3.3.1 Cost-benefit analysis of drug driving enforcement by the police
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November 2006
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Thank you for your attention!
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November 2006
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