November TRB 2012 DRUID session Drug Driving Enforcement Marjan Hagenzieker and Sjoerd Houwing
November TRB 2012 DRUID session Partners KLPD (NL) DTU (DK) THL (FI) SWOV (NL) UGent (BE) TØI (NO)
November TRB 2012 DRUID session 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 ( ), but have they improved since then?
November TRB 2012 DRUID session 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
November TRB 2012 DRUID session 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
November TRB 2012 DRUID session Practical evaluation 8 devices have been qualified as promising: Mavand RapidSTATSecuretec Drugwipe 5+ Branan Oratect XPVarian Oralab 6 Innovacon OrALertCozart DDS Dräger Drug Test 5000Biosensor BIOSENS* * During specific enforcement activities where a great number of persons should be tested in a limited period of time.
November TRB 2012 DRUID session Promising Oral fluid screening devices
November TRB 2012 DRUID session 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
November TRB 2012 DRUID session Analytical evaluation SubstanceSensitivitySpecificityAccuracy Cannabis11-59%90-100%84-98% Amphetamines0-87%90-100%84-98% Cocaine13-50%99-100%86-100% Opiates69-90%81-100%75-99% Benzodiazepines48-67%94-100%77-100% Desired target value: 80% for sensitivity and specificity for all substances Not met by any of the devices!
November TRB 2012 DRUID session 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.
November TRB 2012 DRUID session Task 3.2 Overall sensitivity vs. overall specificity Only DrugTest 5000, RapidSTAT, and Drugwipe 5+ are above the 80% for sensitivity and specificity
November TRB 2012 DRUID session 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.
November TRB 2012 DRUID session Societal cost-benefit analysis (CBA) Costs of increased enforcement Benefits of reduced casualties (valuation of prevented fatalities/injuries/damage) due to increased enforcement Cost-Benefit Analysis
November TRB 2012 DRUID session An increase of drug driving enforcement should not result in a decrease of drink driving enforcement Main conclusions CBA #1
November TRB 2012 DRUID session Oral fluid screening devices that perform above average have a higher Benefit-Cost ratio than devices that perform below average Main conclusions CBA #2 Figure: BC ratios for three quality groups of devices
November TRB 2012 DRUID session Drug driving enforcement is potential beneficial, particularly for countries that currently have a low enforcement level Main conclusions CBA #3 NetherlandsBelgiumFinland Baseline number of drug tests per inhabitants Net benefits 50% increase5,407,26811,844,255438,494 BC ratio 50% increase Net benefits tripling 13,220,74027,232,590-1,335,197 BC ratio tripling Net benefits 10-fold increase 18,297,59924,429,424-21,124,469 BC ratio 10-fold increase
November TRB 2012 DRUID session 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.
November TRB 2012 DRUID session 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
November TRB 2012 DRUID session More information 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
November TRB 2012 DRUID session Thank you for your attention!