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Using a Field Performance Test on an iPad to Evaluate Driving Under the Influence of Cannabis

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ClinicalTrials.gov Identifier: NCT02849587
Recruitment Status : Unknown
Verified May 2018 by Barth Wilsey MD, University of California, San Diego.
Recruitment status was:  Recruiting
First Posted : July 29, 2016
Last Update Posted : May 3, 2018
Sponsor:
Information provided by (Responsible Party):
Barth Wilsey MD, University of California, San Diego

Tracking Information
First Submitted Date  ICMJE July 14, 2016
First Posted Date  ICMJE July 29, 2016
Last Update Posted Date May 3, 2018
Study Start Date  ICMJE January 2017
Estimated Primary Completion Date June 2019   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: January 25, 2017)
Driving Simulation Global Driving Deficit Score (GDDS) [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
The GDDS is comprised of key variables from the simulator tasks (e.g., crashes, running a red light and perception response time for the amber light dilemma, SDLP, SuRT accuracy, time to collision on the gap acceptance task, failure on the audio direction task).
Original Primary Outcome Measures  ICMJE
 (submitted: July 28, 2016)
Driving Simulation Measuring Lane Tracking [ Time Frame: change from baseline every 60 minutes for 7 hours ]
Participants will be instructed to maintain their lane position. The primary outcome is standard deviation of lateral deviation (SDLP) in centimeters.
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: January 25, 2017)
  • Driving Simulation Measuring Deviation of Lateral Position [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    Driving simulation measuring standard deviation of lateral position (in feet) during the SuRT task
  • Driving Simulation Measuring Speed Deviation [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    Participants will be instructed to maintain their speed during the SuRT task. The primary outcome is speed deviation in miles per hour.
  • Driving Simulation Measuring Divided Attention [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    Participants will be instructed to respond to divided attention stimuli in the SuRT task. The primary outcomes are number correct and response latency.
  • Driving Simulation Measuring Car Following - Coherence [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The outcome is coherence between the participant and lead cars (a general correlation [0-1] of the participant's ability to accurately track the speed variations of the lead car).
  • 5. Driving Simulation Measuring Car Following - reaction time to changes in the lead car's speed. [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The outcome is time delay in seconds (response time to changes in the lead car's speed).
  • Driving Simulation Measuring Car Following - distance from the lead car. [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The outcome is distance (number of feet) from the lead car.
  • Driving Simulation Measuring Crash avoidance response time (in milliseconds) [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    In order to assess treatment effects during routine and non-routine events the investigator will include scenarios addressing crash avoidance (e.g., object entering the roadway).
  • Driving Simulation Measuring Yellow Light Dilemma [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    Stopping accuracy and perception response time will be measured after the traffic light turns yellow.
  • Driving Simulation Left Turn Gap Acceptance [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The time to collision with on-coming vehicles will be assessed.
  • Performance-based tablet assessment: Critical Tracking [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The participant will follow a moving target (square) with her/his finger.
  • Performance-based tablet assessment: Time estimation [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The research associate will administer a brief measure of time estimation with randomly generated durations.
  • Performance-based tablet assessment: Balance [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    To assess balance, participants will perform a Modified Romberg Test, without the time estimation component. Circular, forward-backward, and lateral postural sway will be assessed via an accelerometer.
  • Performance-based tablet assessment: Visual Spatial Learning Test [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    Short term memory will be tested using a visual-spatial learning test.
  • Identification of Recent Cannabis Intake Using Whole Blood [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    It has been hypothesized that several cannabinoids (e.g., THC-glucuronide, cannabidiol and cannabinol) might be useful for estimating the last time of cannabis intake The outcome will be the concentration of each cannabinoid expressed in nanograms per milliliter.
  • Assays for Oral Fluid Cannabidiol [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The levels of cannabidiol in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays for Oral Fluid Cannabinol [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The levels of cannabinol in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays for Oral Fluid THC-glucuronide [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The levels of THC-glucuronide in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays of THC in Breath Specimens [ Time Frame: participants will be followed for the duration of an 7 hour, single day human laboratory experiment, and the outcome will be measured once before they receive study medication and then 4 additional times during the treatment day ]
    The THC will be measured in picograms per ml.
Original Secondary Outcome Measures  ICMJE
 (submitted: July 28, 2016)
  • Driving Simulation Measuring Speed Deviation [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    Participants will be instructed to maintain their speed. The primary outcome is speed deviation in miles per hour.
  • Driving Simulation Measuring Divided Attention [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    Participants will be instructed to respond to divided attention stimuli in two corners of the monitor. The primary outcome is percentage accuracy on the divided attention tasks.
  • Driving Simulation Measuring Car Following - Coherence [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    The outcome is coherence between the participant and lead cars (a general correlation [0-1] of the participant's ability to accurately track the speed variations of the lead car).
  • Driving Simulation Measuring Car Following - reaction time to changes in the lead car's speed. [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    The outcome is time delay in milliseconds (reaction time to changes in the lead car's speed.
  • Driving Simulation Measuring Car Following - distance from the lead car. [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    The outcome is distance (number of meters) from the lead car.
  • Driving Simulation Measuring Multi-tasking (Surrogate Reference Task [SuRT])- accuracy [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    The outcome accuracy on the SuRT is measured in standard deviation of lateral deviation (SDLP) during this more challenging divided attention task.
  • Driving Simulation Measuring Multi-tasking (Surrogate Reference Task [SuRT])- response latency. [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    The outcome response latency on the SuRT is measured in milliseconds during this more challenging divided attention task.
  • Driving Simulation Measuring Crash avoidance/decision-making [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    In order to assess treatment effects during routine and non-routine events the investigator will include scenarios addressing 1) the "yellow light dilemma", wherein individuals need to respond to a yellow light onset by abruptly braking (risking a rear-end collision), or go through the intersection (risking running a red light). This will measured dichotomously; crash avoidance yes or no.
  • Performance-based tablet assessment: Critical Tracking [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    Participants will use a stylus on an iPad to overcome built-in error in horizontal deviation from a midpoint by increases as a function of time. The primary outcome is the average lambda-c across 5 trials.
  • Performance-based tablet assessment: Time estimation [ Time Frame: change from baseline of the five estimates of time estimation every 60 minutes for 7 hours ]
    Cannabis can affect time perception and estimation. Deficits in temporal processing could have significant implications for driving, for example in estimating the amount of time available to pass through a yellow light, or anticipating cross- traffic. The investigator will thus administer a brief measure of time estimation. Five trials, with randomly generated durations ranging from 5 to 30s (e.g., 7, 11, 29, 14, 23 seconds), will be generated. During each assessment, participants will complete the five trials. The primary outcome is the difference in time between actual 30 second intervals and guesstimates made by the participant.
  • Performance-based tablet assessment: Balance [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    Individuals may exhibit increased body sway when taking cannabis. To assess balance, participants will hold the iPad to their chest with their arms crossed, and their postural sway will be assessed while: 1) standing on both feet with eyes closed and 2) on a single foot and raising the other leg with the knee bent at 45 degrees, with eyes closed. Sway will be calculated using the iPad triaxial accelerometer.
  • Performance-based tablet assessment: Visual Spatial Learning Test [ Time Frame: participants will be followed for the duration of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 7 hours thereafter on an every 60 minute basis ]
    Cannabis can affect memory acutely. The investigator will assess short term memory using a visual-spatial learning test (VSLT). The test requires the subject to a) memorize 5 designs that are difficult to verbally encode, b) recognize them among a group of 10 distractors (5 foils) and c) recall the correct placement of these designs on a 4 X 4 matrix. Participants will complete one trial. The outcome is the number of figures correctly identified.
  • Identification of Recent Cannabis Intake Using Whole Blood [ Time Frame: change from baseline of the concentrations of cannabinoids every 60 minutes for 7 hours ]
    It has been hypothesized that several cannabinoids (e.g., THC-glucuronide, cannabidiol and cannabinol) might be useful for estimating the last time of cannabis intake. This follows from the finding that analytes of these cannabinoids, at observed Cmax, were not detected beyond 2 h after smoking, rendering them possible candidates for markers of recent cannabis smoking. The outcome will be the concentration of each cannabinoid expressed in nanograms per milliliter.
  • Assays for Oral Fluid Cannabidiol [ Time Frame: participants will be followed for the first 5 hours of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 4 hours thereafter on an every 60 minute basis ]
    The investigator will employ the Quantisal M collection device (Alere Inc., 9975 Summers Ridge Rd, San Diego, CA 92121) to collect and store saliva samples. Using ultra-performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS), the levels of cannabidiol in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays for Oral Fluid Cannabinol [ Time Frame: participants will be followed for the first 5 hours of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 4 hours thereafter on an every 60 minute basis ]
    The investigator will employ the Quantisal M collection device (Alere Inc., 9975 Summers Ridge Rd, San Diego, CA 92121) to collect and store saliva samples. Using ultra-performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS), the levels of cannabinol in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays for Oral Fluid THC-glucuronide [ Time Frame: participants will be followed for the first 5 hours of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 4 hours thereafter on an every 60 minute basis ]
    The investigator will employ the Quantisal M collection device (Alere Inc., 9975 Summers Ridge Rd, San Diego, CA 92121) to collect and store saliva samples. Using ultra-performance liquid chromatography (UPLC) and tandem mass spectrometry (MS/MS), the levels of THC-glucuronide in the oral fluid samples will be determined in nanograms per milliliter.
  • Assays of THC in Breath Specimens [ Time Frame: participants will be followed for the first 4 hours of an 8 hour human laboratory experiment, and the outcome will be measured once before they receive study medication and then for 3 hours thereafter on an every 60 minute basis ]
    Exhaled breath has recently been identified as a matrix for the detection of drugs of abuse including THC. This technology is based on a collecting device, the SensAbues Drug Trap®, that has a filter which traps aerosols from breath. These aerosols mimic the blood in terms of the content of certain substances including THC which will be measured in picograms per ml.
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
 
Descriptive Information
Brief Title  ICMJE Using a Field Performance Test on an iPad to Evaluate Driving Under the Influence of Cannabis
Official Title  ICMJE A Randomized, Controlled Trial of Cannabis in Healthy Volunteers Evaluating Simulated Driving, Field Performance Tests and Cannabinoid Levels
Brief Summary This study was authorized by the California Legislature (Assembly Bill 266, the Medical Marijuana Regulation and Safety Act (73) to help with detection of driving under the influence of cannabis. One hundred and eighty healthy volunteers will inhale smoked cannabis with either 0% (placebo), 5.9%, or 13.4% Δ9-THC at the beginning of the day, and then complete driving simulations, iPad-based performance assessments, and bodily fluid draws (e.g., blood, saliva, breath) before the cannabis smoking and a number of times over the subsequent 6 hours after cannabis smoking. The purpose is to determine (1) the relationship of the dose of Δ9-THC on driving performance and (2) the duration of driving impairment in terms of hours from initial use, (3) if saliva or expired air can serve as a useful substitute for blood sampling of Δ9-THC in judicial hearings and (4) if testing using an iPad can serve as a useful adjunct to the standardized field sobriety test in identifying acute impairment from cannabis.
Detailed Description

There are several studies that suggest higher doses of whole-blood Δ9-THC concentration are associated with increased crash risk and crash culpability. However, attempts to define a cut-off point for blood Δ9-THC levels have proven to be challenging. Unlike alcohol, for which a level can be reasonably measured using a breathalyzer (and confirmed with a blood test), detection of a cut-off point for intoxication related to Δ9-THC concentration has eluded scientific verification. Recent evidence suggests blood Δ9-THC concentrations of 2-5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Others have countered that this level leads to false positives, particularly in heavy cannabis users inasmuch as THC may be detectable in their blood specimens for 12-24 hours after inhalation. Given that 12 to 24 hours is well beyond the likely period of driving impairment, this would appear to be a justifiable objection to a per se cut-off point for a Δ9-THC concentration indicative of impairment. Maximal driving impairment is found 20 to 40 minutes after smoking, and the risk of driving impairment decreases significantly after 2.5 hours, at least in those who smoke 18 mg Δ9-THC or less, the dose often used experimentally to duplicate a single joint. Other studies, however, report residual MVA crash risk when cannabis is used within 4 hours prior to driving.

The roadside examination using the Standardized Field Sobriety Test (SFST) for proof of cannabis-related impairment has not been an ideal alternative to blood levels. Originally devised to evaluate impairment under the influence of alcohol, the SFST is comprised of three examinations administered in a standardized manner by law enforcement officers. The 'Horizontal Gaze Nystagmus' (HGN), the 'One Leg Stand' (OLS) and the 'Walk and Turn' test (WAT) require a person to follow instructions and perform motor activities. During the assessments, officers observe and record signs of impairment. In one study, Δ9-THC produced impairments on overall SFST performance in only 50 % of the participants. In a separate study involving acute administration of cannabis, only 30% of people failed the SFST. This discrepancy in rate of failure was thought to be in part due to the participant's cannabis use history. The reported frequency of cannabis use varied from once a week to once every 2-6 months in the study where there was a failure on the SFST by 50% of the participants. The other study included more frequent users who smoked cannabis on at least four occasions per week.

Based upon the above, another means is needed to help law enforcement officers discern driving under the influence of cannabis. One future possibility is the development of performance-based measures of cannabis-related impairments. This will include testing of critical tracking, time estimation, balance and visual spatial memory learning. The investigators have selected brief measures in order to be practicably administered repeatedly over a short time period, as well as tests that have the potential to translate to a tablet-based format, should there be benefit in possibly including these in future performance-based measures for use in the field by law enforcement officers (e.g., a cannabis-focused field sobriety test).

Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Screening
Condition  ICMJE Cannabis Intoxication
Intervention  ICMJE Drug: cannabis
Participants will smoke a cannabis cigarette ad libitum as per their usual routine
Other Name: marijuana
Study Arms  ICMJE
  • Placebo Comparator: Placebo Cannabis
    Subjects will receive cannabis with placebo THC
    Intervention: Drug: cannabis
  • Experimental: Cannabis with 5.9% THC
    Subjects will receive cannabis with 5.9% THC
    Intervention: Drug: cannabis
  • Experimental: Cannabis with 13.4% THC
    Subjects will receive cannabis with 13.4% THC
    Intervention: Drug: cannabis
Publications *

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Unknown status
Estimated Enrollment  ICMJE
 (submitted: January 25, 2017)
180
Original Estimated Enrollment  ICMJE
 (submitted: July 28, 2016)
60
Estimated Study Completion Date  ICMJE June 2019
Estimated Primary Completion Date June 2019   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Be a licensed driver.
  • Need to have acuity of 20/40 or better, with or without correction on a Snellen Visual Acuity eye chart.

Exclusion Criteria:

  • At the discretion of the examining physician, individuals with significant cardiovascular, hepatic or renal disease, uncontrolled hypertension, and chronic pulmonary disease (eg, asthma, COPD) will be excluded.
  • Unwillingness to abstain from cannabis for 2 days prior to screening and experimental visits
  • Positive pregnancy test
  • A positive result on toxicity screening for cocaine, amphetamines, opiates, and phencyclidine (PCP) will exclude individuals from participation.
  • Unwilling to refrain from driving or operating heavy machinery for four hours after consuming study medication.
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 21 Years to 55 Years   (Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT02849587
Other Study ID Numbers  ICMJE 160641
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE
Plan to Share IPD: Undecided
Responsible Party Barth Wilsey MD, University of California, San Diego
Study Sponsor  ICMJE University of California, San Diego
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Principal Investigator: Thomas Marcotte, PhD University of California, San Diego
PRS Account University of California, San Diego
Verification Date May 2018

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP