Mark B. Johnson

Portal Surveys of Time-Out Drinking Locations A Tool for Studying Binge Drinking and AOD Use

Portal surveys, defined as assessments occurring proximal to the entry point to a high-risk locale and immediately on exit, can be used in different settings to measure characteristics and behavior of attendees at an event of interest. This methodology has been developed to assess alcohol and other drug (AOD) use at specific events and has included measuring intentions to use collected at entry and reported use on exit, as well as chemical tests for AOD consumption at both entrance and exit. Recent applications of the portal survey procedure to electronic music dance events that occur in established venues (e.g., bars or nightclubs) are discussed.

Living Dangerously: Driver Distraction at High Speed

Recent research indicates that cell phone use can distract drivers from safe vehicle operation. However, estimates of the prevalence of cell phone use while driving have been limited to daytime hours and low-speed roadways. This paper describes the results of a study to estimate rates of cell phone use and other distractions by examining approximately 40,000 high-quality digital photographs of vehicles and drivers on the New Jersey Turnpike. The photographs, which originally were collected as part of a separate study, were taken both during the day and during the night and at different locations across the span of the Turnpike. A radar gun linked to the camera recorded the speeds of vehicles as they passed. This provided us with the speeds of every vehicle photographed, and allowed us to determine population counts of vehicles. A panel of three trained coders examined each photograph and recorded the presence of cell phone use by the drivers or any other distracting behavior. Demographic information on the driver was obtained during previous examinations of the photographs for an unrelated study. A rating was considered reliable when two out of the three coders agreed. Population estimates (and confidence intervals) of cell phone use and other distractions were estimated by weighting the cases by the inverse probability of vehicle selection. Logistic regression was used to predict cell phone use from demographic and situational factors. The results indicated that the most frequent distraction was cell phone use: 1.5% of the drivers on the Turnpike were using cell phones compared to the 3 to 4% use rates reported in the National Occupant Protection Use Survey (NOPUS) surveys conducted during the daytime on lower speed roadways. The Turnpike survey indicated that cell phones were used less on weekends and at night, and when the driver was exceeding the speed limit or had a passenger in the car.

Testing the racial profiling hypothesis for seemingly disparate traffic stops on the New Jersey Turnpike

This paper describes two studies designed to produce benchmark values with which to compare police stop data in an effort to assess racial profiling. Racial profiling is often measured by comparing the racial and ethnic distribution from police stop rates to race and ethnicity data derived from regional census counts. However, benchmarks may be more appropriate that are based on (1) the population of drivers or (2) the population of traffic violators. This research surveyed drivers on the New Jersey Turnpike and produced benchmark distributions reflecting these two populations. Benchmark values then were compared to police stops collected from State Troopers patrolling the Turnpike. The results revealed that the racial make‐up of speeders differed from that of nonspeeding drivers and closely approximated the racial composition of police stops. Specifically, the proportion of speeding drivers who were identified as Black mirrored the proportion of Black drivers stopped by police. This finding may explain the differences found between police stop rates and regional census data that are often interpreted as evidence of racial profiling. Interpretation and limitations of the results are discussed.

THE PREVALENCE OF CANNABIS-INVOLVED DRIVING IN CALIFORNIA

BACKGROUND Various national surveys suggest that cannabis use is rising nationally and many States have passed legislation that has potential to increase usage even further. This presents a problem for public roadways, as research suggests that cannabis impairs driving ability. METHODS Anonymous oral fluid samples and breath tests were obtained from more than 900 weekend nighttime drivers randomly sampled from six jurisdictions in California. Oral fluid samples were assayed for the presence of Schedule I drugs. Drivers also completed information on self-reported drug use and possession of a medical cannabis permit. Data from the 2007 National Roadside Survey (collected using comparable methods) were used as a comparison. RESULTS Using the 2010 data, a total of 14.4% of weekend nighttime drivers tested positive for illegal drugs, with 8.5% testing positive for delta-9-tetrahydrocannabinol (THC). THC-positive rates varied considerably among jurisdictions, from a low of 4.3% in Fresno to a high of 18.3% in Eureka. A comparison with the 2007 NRS data found an increase in THC-positive drivers in 2010, but no increase in illegal drugs other than cannabis. Drivers who reported having a medical cannabis permit were significantly more likely to test positive for THC. CONCLUSIONS Cannabis-involved driving has increased in California since 2007. Nearly 1-in-10 weekend, nighttime drivers tested positive for THC, and in some jurisdictions, the rate was nearly 1-in-5. The possible contribution of cannabis legislation, such as decriminalization and medical cannabis usage, is discussed.

PREDICTING DRUG USE AT ELECTRONIC MUSIC DANCE EVENTS: SELF-REPORTS AND BIOLOGICAL MEASUREMENT

Most information on the prevalence of drug use comes from self-report surveys. The sensitivity of such information is cause for concern about the accuracy of self-report measures. In this study, self-reported drug use in the last 48 hr is compared to results from biological assays of saliva samples from 371 young adults entering clubs. The relationship between self-reports and drug presence in oral fluid was determined for three substances as follows: cocaine, marijuana, and amphetamine. Forty-one percent of the participants with drugs detected in their oral fluids reported no use in the last 48 hr. The significance of these results is discussed.

To Reduce Youthful Binge Drinking: Call an Election in Mexico

Tijuanas loosely enforced age-18 drinking limit and low-priced alcohol entices thousands of young Americans to drink. On two weekends in 1997 and 1998, the Mexican government held elections during which alcohol sales were prohibited from midnight Friday night through 10 a.m. Monday. This study reports the effects of the election closings. To detect changes on two election nights, we analyzed the Immigration and Naturalization Service (INS) counts and random breath tests of U.S. residents returning from Tijuana. The total prohibition against liquor sales on election Saturday nights was associated with a 71.2% reduction in total pedestrian returnees and a 34.5% reduction on Friday nights with partial closing of bars. Further, results showed that the number of pedestrians with breath alcohol contents (BACs) at 0.08 or higher was reduced during election days. The closing of Tijuanas alcohol establishments reduced the number of border crossers and the BACs of returnees.

Assessment of club patrons' alcohol and drug use: the use of biological markers.

BACKGROUND Young adulthood (ages 18-25 years) represents a time when high-risk behaviors, including alcohol and drug use, peak. Electronic music dance events (EMDEs) featured at clubs provide an ecologic niche for these high-risk behaviors. PURPOSE This paper examines the prevalence of alcohol and drug use among EMDE patrons. Examination of personal characteristics associated with exit levels of alcohol and drug use identifies important indicators of risk taking for prevention strategies. METHODS Data were collected anonymously during 2010-2012 from 2028 patrons as they entered and exited clubs in the San Francisco Bay area featuring EMDEs. Nearly half were aged ≤25 years. Biological measures of drug and alcohol and self-reported personal characteristics were attained. Analyses were completed in 2012. RESULTS At entrance, more than one fifth of patrons were positive for drug use and one fourth arrived either impaired (blood alcohol concentration [BAC]: 0.05%-0.079%) or intoxicated (BAC: >0.08%) by alcohol. At exit, one fourth tested positive for drugs, and nearly half were impaired or intoxicated by alcohol. Individual characteristics that were important for levels of risk included prior alcohol use behaviors, sexual identity, ethnic/racial identity, and transportation to the event. Gender did not differentiate for alcohol use but fewer women used drugs. CONCLUSIONS Findings confirm the importance of targeting EMDEs for prevention efforts. EMDEs attract young working adults who are engaged in heavy alcohol and/or drug use. Targeting these social settings for delivering public health prevention strategies regarding alcohol and drug use and related harm is indicated by the findings.

Driving Decisions When Leaving Electronic Music Dance Events: Driver, Passenger, and Group Effects

Objectives: The goal of this article was to identify characteristics of drivers and passengers that predicted peer groups whose drivers exit dance clubs with alcohol levels indicative of impairment (blood alcohol content [BAC] ≥ 0.05 g/dL). Methods: We used the portal survey methodology to randomly sample groups of electronic music dance event (EMDE) patrons as they entered and exited a club. From May through November 2010, data were collected from 38 EMDEs hosted by 8 clubs in the San Francisco Bay area. Data included in these analyses are results from breath samples for measuring BAC and self-report data on demographics, recent drinking history drinking, drinking intentions, travel to and from the clubs, and the familiarity/experience with other group members. These data were collected from a subset of 175 drivers and 272 passengers. Results: Although drivers drank less than passengers, one driver in 5 groups had a BAC indicative of elevated crash risk (BAC ≥ 0.05 g/dL). Groups of drivers and/or passengers with a recent history of binge drinking were more likely to have drivers with BACs ≥ 0.05 g/dL. One unanticipated finding was that drivers who knew more group members relatively well were more likely to exit the club with a BAC ≥ 0.05 g/dL. Additionally, we found that groups with all female passengers were at greater risk for having a driver whose BAC was ≥ 0.05 g/dL. Conclusions: Some group characteristics predicted drivers who exit clubs with BACs ≥ 0.05 g/dL. One intervention strategy to promote safety might be to encourage group members to reconsider who is sober enough to drive away from the club; for some groups, a change of drivers would be a safer choice, because a passenger may have a relatively safe BAC. Groups of females appear to have a particularly elevated risk of having a driver whose BAC exceeds 0.05 g/dL, and new intervention efforts should be particularly directed to these at-risk groups.

Alcohol and drug use among young adults driving to a drinking location

BACKGROUND Clubs that feature electronic music dance events (EMDEs) draw young adults aged 18-34 who are at high-risk for alcohol-related crashes to locations where alcohol sales are the principal source of revenue. Up to 30% of these attendees may also use drugs. This provides an important context in which to study driving arrangements that reflect concern with impaired driving. We explored whether drivers were using less alcohol and fewer drugs at exit than their passengers were and whether a driver for the group ever changed after consuming too much during the evening. METHODS Using biological measures of alcohol consumption (breath tests) and drug use (oral fluid tests), 175 drivers and 272 passengers were surveyed among young adults arriving at and departing from EMDEs in San Francisco. RESULTS Upon exit from the drinking locations, only 20% of the drivers, compared to 47% of the passengers, had a high breath alcohol concentration (defined as a BrAC of .05 g/dL or greater). Further, there was evidence that drivers with high BrACs switched to passenger status on exit and former passengers with lower BrACs replaced those drivers. However, there were no differences in the prevalence of drug use among drivers and passengers. CONCLUSIONS These findings suggest that the effort by young adult drivers to avoid alcohol-impaired driving appears to be reducing the number of drivers with high BrACs returning from drinking locations, such as EMDEs, by about one third. However, there is no similar pattern for drugged driving.

The sidewalk survey: a field methodology to measure late-night college drinking

Alcohol use is highly prevalent among U.S. college students, and alcohol-related problems are often considered the most serious public health threat on American college campuses. Although empirical examinations of college drinking have relied primarily on self-report measures, several investigators have implemented field studies to obtain objective measures of alcohol consumption (blood alcohol concentration) from students in ecologically valid settings. This article describes the methodology of breath-test field survey that is being conducted on the grounds of San Diego State University. Descriptive summaries of the data collected through spring 2003 are provided, and limitations to methodology are discussed.