Estimated Blood Alcohol Concentration Research Articles

Prepartying, drinking games, and extreme drinking among college students: A daily-level investigation

IntroductionDaily data collected over 14 consecutive days were used to examine whether extreme drinking was more likely on days college students reported prepartying (i.e., drinking before going out) or playing drinking games in a multi-ethnic sample of college seniors (analysis subsample: N=399; 57% women; M age=21.48years, SD=.40). MethodsMultilevel modeling with drinking occasions at Level 1 (1265 drinking days) nested within persons at Level 2 (399 drinkers) was used to predict four extreme drinking behavior outcomes at the daily level: consuming at least 8/10 (women/men) drinks, reaching an estimated blood alcohol concentration (eBAC) of .16% or greater, drinking enough to stumble, and drinking enough to pass out. ResultsPrepartying only (29% of drinking days) was more common than playing drinking games only (10%) or engaging in both behaviors on the same day (13%). Odds of extreme drinking were greater among students who frequently engaged in prepartying (ORs: 1.86–2.58) and drinking games (ORs: 1.95–4.16), except prepartying frequency did not predict drinking enough to pass out. On days students prepartied (ORs: 1.58–2.02) and on days they played drinking games (ORs: 1.68–1.78), odds of extreme drinking were elevated, except drinking games did not predict eBAC of .16% or greater. ConclusionsExtreme drinking is attributable to both person-level characteristics (e.g., preparty frequency) and specific drinking behaviors on a given day. Prepartying and drinking games confer elevated risk of extreme drinking and are important targets in alcohol interventions for college seniors.

Mobile phone brief intervention applications for risky alcohol use among university students: a randomized controlled study.

BackgroundBrief interventions via the internet have been shown to reduce university students’ alcohol intake. This study tested two smartphone applications (apps) targeting drinking choices on party occasions, with the goal of reducing problematic alcohol intake among Swedish university students.MethodsStudents were recruited via e-mails sent to student union members at two universities. Those who gave informed consent, had a smartphone, and showed risky alcohol consumption according to the Alcohol Use Disorders Identification Test (AUDIT) were randomized into three groups. Group 1 had access to the Swedish government alcohol monopoly’s app, Promillekoll, offering real-time estimated blood alcohol concentration (eBAC) calculation; Group 2 had access to a web-based app, PartyPlanner, developed by the research group, offering real-time eBAC calculation with planning and follow-up functions; and Group 3 participants were controls. Follow-up was conducted at 7 weeks.ResultsAmong 28574 students offered participation, 4823 agreed to join; 415 were excluded due to incomplete data, and 1932 fulfilled eligibility criteria for randomization. Attrition was 22.7–39.3 percent, higher among heavier drinkers and highest in Group 2. Self-reported app use was higher in Group 1 (74%) compared to Group 2 (41%). Per-protocol analyses revealed only one significant time-by-group interaction, where Group 1 participants increased the frequency of their drinking occasions compared to controls (p = 0.001). Secondary analyses by gender showed a significant difference among men in Group 1 for frequency of drinking occasions per week (p = 0.001), but not among women. Among all participants, 29 percent showed high-risk drinking, over the recommended weekly drinking levels of 9 (women) and 14 (men) standard glasses.ConclusionsSmartphone apps can make brief interventions available to large numbers of university students. The apps studied using eBAC calculation did not, however, seem to affect alcohol consumption among university students and one app may have led to a negative effect among men. Future research should: 1) explore ways to increase user retention, 2) include apps facilitating technical manipulation for evaluation of added components, 3) explore the effects of adapting app content to possible gender differences, and 4) offer additional interventions to high-risk users.Trial registrationclinicaltrials.gov: NCT01958398.

Alcohol consumption and partner violence among women entering substance use disorder treatment.

To test the hypothesized role of alcohol consumption as a proximal risk factor for partner violence, a within-subjects analysis compared levels of alcohol consumption in violent versus nonviolent conflict events among substance-abusing women and their male partners. Participants were married or cohabiting women (N = 145) who had recently begun a substance abuse treatment program and reported both a violent and a nonviolent relationship conflict event with their male partner in the prior 6 months. The average age was 38, and 83% were White. Male partners did not participate in the study. The female participant provided information about the male partner. Women were interviewed regarding a violent conflict event in which physical violence occurred and a nonviolent conflict event in which psychological aggression occurred without physical violence. The interview assessed quantity of alcohol consumed and use of other drugs prior to each conflict. Alcohol consumption was significantly greater prior to violent versus nonviolent conflict events for all measures of women's alcohol consumption examined: any drinking, heavy drinking, number of drinks in the 12 hr preceding the conflict event, and estimated blood alcohol concentration at time of the event. Male partners' alcohol consumption showed similar results. Use of other drugs in women, but not men, was significantly more likely prior to physical conflicts. These within-subject comparisons help to rule out individual difference explanations for the alcohol-violence association and indicate that the quantity of alcohol consumption is an important proximal risk factor for partner violence in substance-abusing women and their male partners. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

Dispositional drinking motives: Associations with appraised alcohol effects and alcohol consumption in an ecological momentary assessment investigation.

Alcohol use can be understood as a strategic behavior, such that people choose to drink based on the anticipated affective changes produced by drinking relative to those produced by alternative behaviors. This study investigated whether people who report drinking for specific reasons via the Drinking Motives Questionnaire-Revised (DMQ-R; Cooper, 1994) actually experience the alcohol effects they purportedly seek. As a secondary goal, we examined relations between drinking motives and indices of the amount of alcohol consumed. Data were drawn from 3,272 drinking episodes logged by 393 community-recruited drinkers during a 21-day Ecological Momentary Assessment investigation. After accounting for selected covariates, DMQ-R enhancement motives uniquely predicted real-time reports of enhanced drinking pleasure. DMQ-R coping motives were associated with reports of increased drinking-contingent relief and punishment. Enhancement motives uniquely predicted consuming more drinks per episode and higher peak intra-episode estimated blood alcohol concentration. The findings extend the evidence for the validity of the DMQ-R motive scores by demonstrating that internal drinking motives (enhancement and coping) are related to the experienced outcomes of drinking in the manner anticipated by theory.

P.4.010 Intellectual changes and structural network development in adolescence

In the United States, turning 21 often involves heavy drinking and high rates of alcohol-related consequences. Friends are an important source of social influence on young adult drinking, including during 21st birthdays. However, research is needed to investigate the specific pathways through which this interpersonal influence occurs. Data were drawn from a larger intervention study focused on reducing 21st birthday drinking. Using data from 166 celebrant and friend dyads (N = 332 individuals), we prospectively examined relations among each person’s beliefs about 21st birthday celebrations, drinking intentions for the celebrant, and celebrants’ estimated blood alcohol concentration (eBAC) on their 21st birthdays. Path analyses evaluated the impact of celebrant and friend beliefs on their own report of celebrant intentions, each other’s report of celebrant intentions, and celebrant eBAC, as well as the mediating role of each individual’s report of celebrant intentions. Results revealed significant indirect effects of each individual’s beliefs on celebrant eBAC via their own report of celebrant 21st birthday drinking intentions. Friend beliefs also predicted celebrant eBAC via celebrant drinking intentions, beyond the effect of celebrant beliefs. Importantly, celebrant eBAC was as strongly predicted by friend 21st birthday celebration beliefs as they were by their own beliefs. Results highlight multiple pathways through which friends influence 21st birthday drinking and reveal that friend influence is not constrained to the celebration, but begins in advance of the event by shaping celebrants’ drinking intentions. Findings highlight key directions for future work leveraging friends as intervention agents to reduce drinking related to this high-risk event.

Description and Predictors of Positive and Negative Alcohol-Related Consequences in the First Year of College

The purpose of this study was to establish the frequency of positive and negative alcohol-related consequences during the first year of college and to evaluate gender, race/ethnicity, time of year, alcohol use, and intoxication as predictors of consequences using frequent assessments. Participants (N = 1,053; 57.5% female) completed biweekly assessments of alcohol use and positive and negative alcohol-related consequences throughout the year. The majority of drinkers reported both positive and negative consequences. Having a good time and feeling less stressed were the most commonly reported positive consequences. Blackouts and getting physically sick were the most commonly endorsed negative consequences. At the weekly level, number of drinking days, drinks per drinking day, and estimated blood alcohol concentration (eBAC, reflecting intoxication) were significantly related to all consequences after controlling for demographics and time of year. Negative consequences had stronger associations with number of drinks and eBAC than positive consequences did. With each additional drink consumed on a drinking day, the incidence of negative consequences more than doubled (incidence rate ratio [IRR] = 2.34, 95% CI [2.19, 2.50]), whereas the incidence of positive consequences increased by about half (IRR = 1.51, 95% CI [1.47, 1.56]). The consequence with the largest gender difference was regretted sex, with women reporting it more often. Few racial/ethnic differences were found in report of negative consequences. Greater positive and negative consequences were endorsed at the beginning of both academic semesters. As number of drinks and eBAC increase, the relative odds of a negative consequence are higher than that of a positive consequence. Alcohol interventions could promote greater awareness of the likelihood of specific consequences and could highlight that positive consequences are associated with lower levels of drinking.

Predictors and consequences of pregaming using day- and week-level measurements.

Drinking before going to a social event is common in adolescents and young adults and is associated with harmful outcomes, but information collected at the daily level is needed to better examine individual and contextual factors associated with pregaming. The purpose of this study was to investigate the prevalence of pregaming in a diverse sample of college students; demographic differences in rates of pregaming; the degree to which pregaming is associated with higher volume drinking, intoxication, and consequences; and the importance of time-of-year and day-of-week. College students (N = 750) at three colleges completed past-week surveys throughout their freshman and sophomore years. Pregaming was reported by 3 out of 4 drinkers and occurred on 31% of 12,361 drinking days. Compared with nonpregaming days, participants drank approximately 2 more drinks on pregaming days; this increase accounted for a .040 higher estimated blood alcohol concentration. Using generalized estimating equations, we established that women, racial/ethnic minority students, and first-year students were more likely to pregame on a drinking day than males, non-Hispanic White students, and sophomore students, respectively. Men became more intoxicated on pregaming days and sophomores consumed more alcohol. Pregaming predicted higher positive and higher negative consequences, even after controlling for the number of drinks consumed. Pregaming was more common in the fall semester, in the early weeks of each semester, and on weekends. Prevention efforts targeting first-year students, the early weeks of the semester, and the hours before traditional party times may be effective at reducing this hazardous practice.

A computer-based feedback only intervention with and without a moderation skills component

Research on the efficacy of computer-delivered feedback-only interventions (FOIs) for college alcohol misuse has been mixed. Limitations to these FOIs include participant engagement and variation in the use of a moderation skills component. The current investigation sought to address these limitations using a novel computer-delivered FOI, the Drinkers Assessment and Feedback Tool for College Students (DrAFT-CS). Heavy drinking college students (N=176) were randomly assigned to DrAFT-CS, DrAFT-CS plus moderation skills (DrAFT-CS+), moderation skills only (MSO), or assessment only (AO) group, and were assessed at 1-month follow-up (N=157). Participants in the DrAFT-CS and DrAFT-CS+groups reported significantly lower estimated blood alcohol concentrations (eBACs) on typical heaviest drinking day than participants in the AO group. The data also supported the incorporation of a moderation skills component within FOIs, such that participants in DrAFT-CS+group reported significantly fewer drinks per week and drinks per heaviest drinking occasion than participants in the AO group.

Controlled Attention and Sleep Deprivation: Adding a Self-Regulation Approach?

The current study examined performance on an automated task battery under short-term sleep deprivation and non-sleep deprivation conditions. Twenty-six volunteers completed the sleep deprivation study. Twenty-three volunteers completed the non-sleep deprivation study. Performance was examined across five test sessions during 25 hours of acute sleep deprivation conditions and during two days of non-sleep deprivation conditions. ANOVAs examining changes in performance from baseline levels indicated that performance under sleep deprivation conditions resulted in a decrease in performance in some tasks and an increase in estimated blood alcohol concentration. Non-sleep deprivation resulted in stable or increasing performance and a decrease in estimated blood alcohol concentration. The Controlled Attention Model suggests that the task characteristics would have helped maintain performance levels but does not explain how performance decreased on some but not all of the tasks. Extending the Controlled Attention Model to include a broader self-regulation approach suggests that on some of the tasks the participants did not adequately regulate their engagement in the task (even with rapidly changing stimuli) resulting in a decrease in performance levels. Incorporating a self-regulation approach with the Controlled Attention Model could provide a model that better explains the range of effects seen under sleep deprivation conditions.

"Let's get Wasted!" and Other Apps: Characteristics, Acceptability, and Use of Alcohol-Related Smartphone Applications.

BackgroundSmartphone applications (“apps”) offer a number of possibilities for health promotion activities. However, young people may also be exposed to apps with incorrect or poor quality information, since, like the Internet, apps are mostly unregulated. Little is known about the quality of alcohol-related apps or what influence they may have on young people’s behavior.ObjectiveTo critically review popular alcohol-related smartphone apps and to explore young people’s opinions of these apps, their acceptability, and use for alcohol-related health promotion.MethodsFirst, a content analysis of 500 smartphone apps available via Apple iTunes and Android Google Play stores was conducted. Second, all available blood alcohol concentration (BAC) apps were tested against four individual case profiles of known BAC from a previous study. Third, two focus group discussions explored how young people use alcohol-related apps, particularly BAC apps.Results384 apps were included; 50% (192) were entertainment apps, 39% (148) were BAC apps, and 11% (44) were health promotion and/or stop drinking–related apps. When testing the BAC apps, there was wide variation in results, with apps tending to overestimate BAC scores compared with recorded scores. Participants were skeptical of the accuracy of BAC apps, and there was an overall concern that these apps would be used as a form of entertainment, further encouraging young people to drink, rather than reduce their drinking and risk taking.ConclusionsThe majority of popular alcohol-related apps encouraged alcohol consumption. Apps estimating blood alcohol concentration were widely available but were highly unreliable. Health departments and prominent health organizations need to endorse alcohol smartphone apps that are accurate and evidence-based to give specific apps credibility in the ever-expanding market of unregulated apps.

Ethanol and drug findings in women consulting a Sexual Assault Center – Associations with clinical characteristics and suspicions of drug-facilitated sexual assault

The purpose of the study was to describe toxicological findings among women seeking health care after sexual assault, and to assess the relationship with so-called proactive DFSA (drug facilitated sexual assault). We also explored associations between ethanol in blood/urine and background data, assault characteristics, and clinical findings.We conducted a retrospective, descriptive study of female patients ≥12 years of age consulting the Sexual Assault Center at St. Olavs University Hospital, Trondheim, Norway. They were examined between July 1, 2003 and December 31, 2010, and urine and/or blood were analyzed for ethanol and selected medicinal/recreational drugs.Among the 264 patients included, ethanol and/or drugs were detected in 155 (59%). Of the 50 patients (19%) testing positive for drugs other than ethanol, benzodiazepines/benzodiazepine-like drugs were found in 31, central stimulants in 14, cannabinoids in 13 and opioids in nine. None tested positive for gamma-hydroxybutyrate (GHB). In total, 57 patients (22%) suspected proactive DFSA, but only five had findings of sedative drugs that were not accounted for by self-reported voluntary intake. No cases could unequivocally be attributed to proactive DFSA.Among the 120 patients tested for ethanol within 12 h after the assault, 102 were positive. The median estimated blood alcohol concentration (BAC) at the time of assault was 1.87 g/L. Patients testing positive for ethanol more often reported a public place of assault and a stranger assailant. Higher estimated BAC at the time of assault was associated with higher frequency of suspecting proactive DFSA.Ethanol was the most prevalent toxicological finding in urine/blood from victims of sexual assault, and high ethanol concentrations were often detected. Among the patients suspecting proactive DFSA, very few had sedative drug findings not explained by voluntary intake. It seems like opportunistic DFSA, rather than proactive DFSA dominate among the sexually assaulted attending our SAC.

Relationship Between Blood Alcohol Concentration and Observable Symptoms of Intoxication in Patients Presenting to an Emergency Department

Clinical and medico-legal decisions often require knowledge of alcohol impairment that is not necessarily revealed by an individual's appearance, and in turn, may not necessarily reflect level of blood alcohol. This study compares clinical signs and symptoms with measured and estimated blood alcohol concentrations (BACs). Individuals (n = 384) perceived to be under the influence of alcohol at presentation to an emergency department were assessed by physicians and nurses for clinical features of alcohol intoxication (alcohol symptom checklist, ASC), who were asked to estimate the patient's BAC. Relation to measured BACs was assessed by correlation. BACs ranged from 0 to 418 mg/100 ml. The correlation between the estimated BAC and measured BAC was r = 0.513. Measured BAC correlated with ASC r = 0.250. In subjects without a history of chronic drinking (n = 134) there was a better (P < 0.05) correlation with the ASC score (r = 0.363) versus measured BAC compared with that for chronic drinkers (r = 0.154). The positive predictive value of estimating BAC at or above a particular BAC cut-off decreased from 93.2% at 100 mg/100 ml to 37.7% at 300 mg/100 ml (P < 0.05). Measured BAC does not correlate well with the outward physical signs of intoxication, especially for chronic drinkers. There is a need for further education on how tolerance masks clinical signs of intoxication for the chronic drinker. BACs should be measured especially in the obtunded where no history (symptoms) can be given by the patient.

An event-level examination of sex differences and subjective intoxication in alcohol-related aggression.

Laboratory-based experimental research has demonstrated that the pharmacological effects of alcohol can increase aggressive responding. Given mixed findings and concerns regarding task validity, however, it remains uncertain whether this effect holds constant across men and women and whether variability in subjective alcohol intoxication contributes to alcohol-related aggression. In this investigation, the authors used 4 years of event-level data in a sample of 1,775 college students (140,618 total observations) to provide a test of laboratory-derived findings on the link between alcohol and aggression in an alternative methodology. They found support for several such findings: (a) Within-person increases in alcohol intoxication, as assessed by estimated blood alcohol concentrations (eBACs), were associated with increases in the probability of aggression at the drinking-episode level; (b) this association was significantly stronger among men than among women; and (c) within-person variability and between-persons individual differences in levels of subjective alcohol intoxication were associated with aggression over and beyond eBACs. Cross-methodological replication can reduce the impact of constraints specific to experimental studies on conclusions regarding alcohol's relation with aggression.

Role of Tobacco Smoking in Hangover Symptoms Among University Students

Although hangover results from excessive alcohol consumption, the specific pathways through which hangover symptoms arise have not been elucidated. Research on predictors of hangover sensitivity may provide clues about such mechanisms. The present study investigated whether tobacco smoking on days of heavy drinking affects next-day hangover incidence and severity. The study drew on diary data from a study on smoking and drinking among 113 students at a midwestern university in the United States. Participants completed a daily, web-based, 26-item survey for 8 weeks to assess prior-day alcohol and tobacco use as well as current-day hangover symptoms. Hierarchical linear modeling was used to test the hypothesis that amount of smoking is related to hangover, controlling for amount of alcohol consumed, sex, and other individual characteristics. Analyses were conducted after selecting only days with alcohol consumption levels that typically elicit hangover, then repeated on lighter drinking days for comparison. Validity of the hangover items was checked by comparing reports after such heavy drinking days with days of lighter drinking. Across all possible person-days, 92% of daily reports were obtained. When selecting only events where an estimated blood alcohol concentration of 110 mg/dl was attained, smoking significantly increased the odds of hangover incidence and hangover severity while controlling for number of drinks consumed and sex. Additional analyses controlling for age first smoked regularly, frequency of drug use, type of drug involvement, or smoking status resulted in findings that were unchanged. Smoking more on heavy drinking days affects hangover sensitivity and severity, possibly because of acute pharmacological effects.

Measurement of alcohol hangover severity: development of the Alcohol Hangover Severity Scale (AHSS)

This study aims to develop a new alcohol hangover symptom severity scale and compare its effectiveness with the Hangover Symptoms Scale (HSS), the Acute Hangover Scale (AHS), and a one-item hangover score. Data from 1,410 Dutch students (Penning et al., Alcohol Alcohol 47:248-252, 2012) on the severity of 47 hangover symptoms were re-analyzed to develop the Alcohol Hangover Severity Scale (AHSS). The psychometric properties of the AHSS were compared with those of the HSS and the AHS. A survey among 1,000 students compared the AHSS and HSS with a one-item hangover severity score. The AHSS was further tested in a naturalistic hangover experiment. The 12 items of the AHSS were fatigue, clumsiness, dizziness, apathy, sweating, shivering, nausea, heart pounding, confusion, stomach pain, concentration problems, and thirst. The Penning et al. (Alcohol Alcohol 47:248-252, 2012) data revealed that the predictive validity of the AHSS (92.4 %) for the overall hangover score was significantly higher than that of the HSS (81.5 %) and the AHS (71.0 %). The survey data (N = 966) showed that scores on the AHSS (39.7 %) and the HSS (47.6 %) only moderately predicted the one-item hangover score. A total of 119 subjects completed the naturalistic study. On average, they consumed 9.7 alcoholic consumptions, yielding a mean estimated blood alcohol concentration (BAC) of 0.16 %. During hangover, the AHSS score correlated significantly with the number of alcoholic consumptions (r = 0.38, p < 0.0001) and estimated BAC (r = 0.40, p < 0.0001). The AHS, HSS, and AHSS all seem appropriate for application in hangover research. The use of a one-item hangover scale is not recommended.

Sex differences in alcohol misuse and estimated blood alcohol concentrations among emergency department patients: implications for brief interventions.

The objective was to assess the relationship between alcohol use and misuse and patient sex among emergency department (ED) patients by comparing self-reported estimates of quantity and frequency of alcohol use, estimated blood alcohol concentrations (eBACs) when typically drinking and during heavy episodic drinking (binging), and alcohol misuse severity, to understand sex differences in alcohol use and misuse for this population. The authors surveyed a random sample of nonintoxicated, subcritically ill or injured, 18- to 64-year-old English- or Spanish-speaking patients on randomly selected dates and times at two EDs during July 2009 and August 2009. Participants self-administered a questionnaire about their self-reported alcohol use during a typical month within the past 12 months and the Alcohol Use Disorders Identification Test (AUDIT). Using the formulae by Matthews and Miller, sex-specific eBACs were calculated for participants according to their reported weight and the number of reported alcoholic drinks consumed on days when typically drinking and on days of heavy episodic (binge) drinking (five or more drinks/occasion for men, four or more drinks for women). Sex-specific alcohol misuse severity levels (low-risk, harmful, hazardous, and dependence) were calculated using AUDIT scores. Wilcoxon rank-sum and Pearson's chi-square tests were used to compare outcomes by sex. Negative binomial regression was used to assess the relationship between sex and the number of drinks consumed on a typical day, the number of days spent drinking and binging, and estimated AUDIT scores. Logistic regression was used to assess the outcome of the presence of binging according to sex. Multinomial logistic regression was used to compare by sex the percentage of days spent drinking and binging in 1 month, eBACs when typically drinking and when binging, and AUDIT at-risk drinking levels. Incidence rate ratios (IRRs) and adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were estimated. All models were adjusted for patient demographic characteristics. Of the 513 participants, 52.1% were women, 55.8% were white non-Hispanic, and their median age was 34 years (interquartile range [IQR] = 25 to 46 years). Men reported greater mean alcohol consumption than women when typically drinking (4.3 vs. 3.3 drinks/day; p < 0.001) and during heavy episodic drinking (8.6 vs. 5.3 drinks/occasion; p < 0.001). Men spent more days drinking (IRR = 1.41, 95% CI = 1.19 to 1.65) and engaging in heavy episodic drinking (IRR = 1.68, 95% CI = 1.31 to 2.17) than women. Additionally, men were more likely to engage in heavy episodic drinking (AOR = 1.72, 95% CI = 1.16 to 2.56) than women. However, the mean eBACs for men and women were similar when typically drinking (0.05 vs. 0.06; p < 0.13) and during heavy episodic drinking (0.13 vs. 0.12; p < 0.13). Mean AUDIT scores were greater for men than women (7.5 vs. 5.3; p < 0.001), although alcohol misuse severity levels were similar between men and women (24.4% vs. 26.6% for hazardous, 2.8% vs. 2.2% for harmful, and 6.5% vs. 3.4% for dependence; p < 0.38). Although men drink more than women, women have similar eBACs with comparable levels of alcohol misuse. Women may benefit from recognizing that they are reaching similar levels of intoxication compared to men. Addressing these differences and possible health implications in future ED brief interventions may induce changes in problematic alcohol use among women.

Daily Variations in Spring Break Alcohol and Sexual Behaviors Based on Intentions, Perceived Norms, and Daily Trip Context

Given the known risks of alcohol use and sexual behavior for college students on Spring Break, this study was designed to document the behaviors and correlates associated with being on a Spring Break trip on a given day (controlling for average time on a trip). Participants were undergraduate students (n = 261; 55% women) who reported that they planned to go on a Spring Break trip. Web-based survey responses before and after Spring Break documented perceived norms, intentions, and actual behavior on each of the 10 days of Spring Break. Students who went on longer trips, who previously engaged in more heavy episodic drinking, or who had greater pre-Spring Break intentions to drink reported greater alcohol use during Spring Break. Similarly, students with greater pre-Spring Break intentions to have sex, greater perceived norms for sex, or more previous sexual partners had greater odds of having sex. On days students were on trips, they had a greater likelihood of having sex, drinking to higher estimated blood alcohol concentrations, consuming more drinks, and reporting perceived drunkenness than on nontrip days, especially if they had intentions to have sex and drink alcohol (and, for models predicting sexual behavior and drunkenness, had greater perceived norms for sex and drinking). Students who went on Spring Break trips engaged in more risk behaviors. In addition, the context of being on a trip on a given day was associated with increased risk, especially if they had stronger intentions and, in some cases, higher perceived norms. Further research is needed to describe the contexts of Spring Break trips and how to intervene effectively.

Responses to alcohol and cigarette use during ecologically assessed drinking episodes

Tobacco and alcohol are frequently used together, and this may be partly explained by a distinct profile of subjective effects associated with co-administration. Ecological momentary assessment studies have examined effects of naturally occurring co-use, but, to date, have not assessed differing effects as alcohol levels rise and fall. The objective of the study was to describe subjective states and appraisals of cigarette and alcohol effects reported during the entirety of real-world drinking episodes. Currently-smoking frequent drinkers (N = 255) carried electronic diaries for 21 days. Analyses focused on reports made during 2,046 drinking episodes. Signaled prompts intensively oversampled moments in the hours following consumption of the first drink in an episode. Multilevel regression analyses were used to predict ratings of buzz, dizziness, excitement, and sluggishness as a function of person-level and contextual covariates, estimated blood alcohol concentration (eBAC) level, ascending vs. descending eBAC, smoking, and their interactions. Appraisals of cigarette and alcohol effects were also examined within this framework. Buzz, excitement, and pleasure from alcohol and cigarettes were prominent features of real-world drinking episodes. Smoking was associated with enhanced buzz and excitement when eBAC was high and descending. Smoking slightly accentuated the relation between eBAC and ratings of drinking pleasure among women, but this relation was somewhat weakened by smoking among men. Smoking during drinking episodes may be partly explained by a persistence of stimulant alcohol effects beyond the blood alcohol concentration peak. Acute effects of nicotine and tobacco use on the descending limb deserve further scrutiny in experimental alcohol challenge research.

Event-level associations between objective and subjective alcohol intoxication and driving after drinking across the college years.

Heavy episodic drinking is strongly associated with driving after drinking, yet there has been mixed evidence regarding whether the disinhibiting effects of alcohol intoxication contribute to the decision to drive after drinking. This investigation tested whether greater alcohol intoxication increased the probability of driving after drinking particularly during drinking episodes in which students experienced reduced subjective feelings of intoxication. A sample of 1,350 college students completed up to 30 days of web-based daily diary monitoring in each of 4 consecutive years. Participants reported daily on their alcohol consumption, subjective intoxication, and whether they drove after drinking on the previous day or night. In generalized estimating equation models, daily estimated blood alcohol concentration (eBAC) was more strongly associated with driving after drinking during episodes in which subjective intoxication was lower. That is, students were most likely to drive after drinking when they were objectively more intoxicated but perceived themselves as less intoxicated. These event-level associations did not change over time nor did they differ as a function of gender. Further, the effects persisted when predicting driving at eBACs above the legal limit for operating a motor vehicle. Greater subjective intoxication may serve to inhibit driving after drinking, particularly when students are objectively more intoxicated. In the absence of subjective intoxication, however, other salient pressures might impel driving after drinking. Prevention efforts should incorporate the importance of variability in subjective intoxication.

21st birthday drinking and associated physical consequences and behavioral risks.

Twenty-first birthday celebrations often involve dangerously high levels of alcohol consumption, yet little is known about risk factors for excessive drinking on this occasion. Participants (N = 150) from a larger prospective study who consumed at least one drink during their celebration completed questionnaires and semistructured interviews about their 21st birthday within four days after the event. Assessments were designed to characterize 21st birthday alcohol use, adjusted for alcohol content, as well as situational/contextual factors (e.g., celebration location, peer influence) that contribute to event-level drinking. Participants reported an average of 10.85 drinks (9.76 adjusted drinks), with experienced drinkers consuming significantly more than relatively naïve drinkers who had no previous binge or drunken episodes. Men consumed more drinks, whereas age of first drunken episode and heavier drinking during the 3-months preceding the 21st birthday predicted higher estimated blood alcohol concentrations (eBACs) on the 21st birthday. Celebrating in bars and engaging in birthday-specific drinking traditions (free drinks at bars) explained additional variance in 21st birthday eBACs. Both physical consequences (e.g., blacking out or having a hangover) and behavioral risks (e.g., sexually provocative behaviors) were prevalent and were predicted by higher eBACs. Together these findings indicate that 21st birthday celebrations are associated with heavy drinking and a variety of physical consequences and behavioral risks.