Carmen V. Voogt

Using ecological momentary assessment to test the effectiveness of a web-based brief alcohol intervention over time among heavy-drinking students: randomized controlled trial.

Background Web-based brief alcohol interventions are effective in reducing alcohol use among students when measured at limited follow-up time points. To date, no studies have tested Web-based brief alcohol intervention effectiveness over time by using a large number of measurements. Objective Testing whether the What Do You Drink (WDYD) Web-based brief alcohol intervention can sustain a reduction in alcohol use among heavy-drinking students aged 18-24 years at 1-, 3-, and 6-month follow-up intervals. Methods A purely Web-based, 2-arm, parallel-group randomized controlled trial applying an ecological momentary assessment approach with 30 weekly measurements was conducted in the Netherlands (2010-2011). Participants were recruited offline and online. A total of 907 participants were randomized into the experimental condition (n=456) including the single-session and fully automated WDYD intervention, or into the control condition (n=451) including assessment only. Weekly alcohol consumption and frequency of binge drinking were the self-assessed outcome measures. Results Attrition rates of the 907 participants were 110 (12.1%), 130 (14.3%), and 162 (17.9%) at 1-, 3-, and 6-month follow-up intervals, respectively. Latent growth curve analyses according to the intention-to-treat principle revealed that participants in the experimental condition had significantly lower weekly alcohol consumption compared to participants in the control condition that was sustained at 3-month follow-up (intercept=–2.60, P<.001; slope=0.16, P=.08). Additional linear regression analyses indicated that this intercept difference resulted from significantly higher levels of alcohol units per week for participants in the control condition compared to those in the experimental condition at 1-month (beta=–2.56, SE 0.74, Cohen’s d=0.20, P=.001), 3-month (beta=–1.76, SE 0.60, Cohen’s d=0.13, P=.003), and 6-month (beta=–1.21, SE 0.58, Cohen’s d=0.09, P=.04) follow-up intervals. Latent growth curve analyses further indicated that participants in the experimental condition had a significantly lower frequency of binge drinking compared to participants in the control condition that was sustained at 6-month follow-up (intercept=–0.14, P=.01; slope=0.004, P=.19). This intercept difference resulted from higher levels in this outcome for participants in the control condition relative to participants in the experimental condition at 1-month (beta=–1.15, SE 0.06, Cohen’s d=0.16, P=.01), 3-month (beta=–0.12, SE 0.05, Cohen’s d=0.09, P=.01), and 6-month (beta=–0.09, SE 0.05, Cohen’s d=0.03, P=.045) follow-up intervals. Conclusions The WDYD intervention was shown to be effective in preventing an increase in weekly alcohol consumption and frequency of binge drinking directly after the intervention. This effect was sustained 3 and 6 months after the intervention. Trial Registration Netherlands Trial Register NTR2665; http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2665 (Archived by WebCite at http://webcitation.org/6LuQVn12M).

Targeting young drinkers online: the effectiveness of a web-based brief alcohol intervention in reducing heavy drinking among college students: study protocol of a two-arm parallel group randomized controlled trial

BackgroundThe prevalence of heavy drinking among college students and its associated health related consequences highlights an urgent need for alcohol prevention programs targeting 18 to 24 year olds. Nevertheless, current alcohol prevention programs in the Netherlands pay surprisingly little attention to the drinking patterns of this specific age group. The study described in this protocol will test the effectiveness of a web-based brief alcohol intervention that is aimed at reducing alcohol use among heavy drinking college students aged 18 to 24 years old.Methods/DesignThe effectiveness of the What Do You Drink web-based brief alcohol intervention will be tested among 908 heavy drinking college students in a two-arm parallel group randomized controlled trial. Participants will be allocated at random to either the experimental (N = 454: web-based brief alcohol intervention) or control condition (N = 454: no intervention). The primary outcome measure will be the percentage of participants who drink within the normative limits of the Dutch National Health Council for low-risk drinking. These limits specify that, for heavy alcohol use, the mean consumption cannot exceed 14 or 21 glasses of standard alcohol units per week for females and males, respectively, while for binge drinking, the consumption cannot exceed five or more glasses of standard alcohol units on one drinking occasion at least once per week within one month and six months after the intervention. Reductions in mean weekly alcohol consumption and frequency of binge drinking are also primary outcome measures. Weekly Ecological Momentary Assessment will measure alcohol-related cognitions, that is, attitudes, self-efficacy, subjective norms and alcohol expectancies, which will be included as the secondary outcome measures.DiscussionThis study protocol describes the two-arm parallel group randomized controlled trial developed to evaluate the effectiveness of a web-based brief alcohol intervention. We expect a reduction of mean weekly alcohol consumption and frequency of binge drinking in the experimental condition compared to the control condition as a direct result of the intervention. If the website is effective, it will be implemented in alcohol prevention initiatives, which will facilitate the implementation of the protocol.Trial registrationNetherlands Trial Register NTR2665.

Longitudinal associations between descriptive and injunctive norms of youngsters and heavy drinking and problem drinking in late adolescence

Cross-sectionally, social norms are related to heavy and problem drinking in late adolescence. A better understanding is needed regarding the longitudinal associations between social norms in younger populations and heavy and problem drinking over time. This study distinguished between descriptive (proximal reference group) and injunctive norms (proximal and distal reference groups). This study evaluated the perception of social norms in youngsters during early adolescence (13–15 years) and the contribution of these norms to heavy and problem drinking over a 4-year period. Adolescents (N = 428; 205 boys) participated in a prospective study with 5 annual waves. Regression analyses were conducted to examine whether descriptive and injunctive norms prospectively predict heavy and problem drinking. Descriptive and injunctive norms of the proximal, but not the distal reference group, predicted heavy drinking in late adolescence. Descriptive norms of the proximal reference group also predicted problem drinking in late adolescence. This study demonstrates the role of social norms in the prediction of heavy and problem drinking over time. Additionally, it illustrates the contribution of proximal rather than distal reference peers to heavy and problem drinking in late adolescence, and it suggests the relevance of targeting these norms in prevention research.

Using Ecological Momentary Assessment in Testing the Effectiveness of an Alcohol Intervention: A Two-Arm Parallel Group Randomized Controlled Trial

Background Alcohol consumption of college students has a fluctuating nature, which might impact the measurement of intervention effects. By using 25 follow-up time-points, this study tested whether intervention effects are robust or might vary over time. Methods Data were used from a two-arm parallel group randomized controlled trial applying ecological momentary assessment (EMA) with 30 data time-points in total. Students between 18 and 24 years old who reported heavy drinking in the past six months and who were ready to change their alcohol consumption were randomly assigned to the experimental (n = 456: web-based brief alcohol intervention) and control condition (n = 451: no intervention). Outcome measures were weekly alcohol consumption, frequency of binge drinking, and heavy drinking status. Results According to the intention-to-treat principle, regression analyses revealed that intervention effects on alcohol consumption varied when exploring multiple follow-up time-points. Intervention effects were found for a) weekly alcohol consumption at 1, 2, 3, 4, and 7 weeks follow-up, b) frequency of binge drinking at 1, 2, 7, and 12 weeks follow-up, and c) heavy drinking status at 1, 2, 7, and 16 weeks follow-up. Conclusions This research showed that the commonly used one and six month follow-up time-points are relatively arbitrary and not using EMA might bring forth erroneous conclusions on the effectiveness of interventions. Therefore, future trials in alcohol prevention research and beyond are encouraged to apply EMA when assessing outcome measures and intervention effectiveness. Trial registration Netherlands Trial Register NTR2665

Alcohol-related cognitions in children (aged 2-10) and how they are shaped by parental alcohol use: A systematic review

BACKGROUND This systematic review aims to summarize the evidence of the impact of parental alcohol use on the acquisition of childrens alcohol-related cognitions (alcohol-related knowledge, alcohol-related norms, alcohol expectancies) in the developmental period from age two to ten. METHODS A computer-assisted systematic literature search was performed in PubMed, PsychINFO, ERIC, and EMBASE. Overall, 20 out of the 3406 unique articles identified in the first screening were included. RESULTS The results revealed that children acquire knowledge about alcohol already at age two and from age four on, they understand its use in adult culture. By the age of four, children have certain alcohol expectancies. The evidence of the impact of parental alcohol use on the acquisition of childrens alcohol-related cognitions is inconsistent so far with studies showing positive and no effects. Unfortunately, the existing evidence is limited because most studies a) were conducted exclusively in the United States and more than two decades ago, b) used cross-sectional study designs, and c) used non-representative samples recruited using convenience sampling strategies. CONCLUSIONS Research on childrens alcohol-related cognitions is underdeveloped. To elucidate the conclusions about alcohol involvement in early life, studies with longitudinal study designs need to be conducted among representative samples of children and early adolescents by using age-appropriate measurement tools in a broader cultural context.

Development of alcohol expectancies and early alcohol use in children and adolescents: A systematic review

PURPOSE Developmental changes in alcohol expectancies (AE) have been proposed to lead to alcohol use initiation and later alcohol use in adolescence. This systematic review aims to provide longitudinal evidence of the development of AE and the relation of AE to alcohol outcomes from childhood to late adolescence (4-18 years old). METHODS A computer-assisted search of relevant articles identified 1602 studies, of which 43 studies (conducted between 1996 and 2016) were selected. RESULTS First, negative AE decline and positive AE increase in early adolescence. Moreover, alcohol use (initiation) seems to strongly influence changes in AE. Second, AE predict alcohol use initiation and drinking patterns over time. Third, longitudinal predictors of AE could be divided into individual predictors (i.e., alcohol-related cognitions, psychopathology, and genetics) and environmental predictors (i.e., family, peer, and media influences). Lastly, the results indicated that AE function as mediators of the relations between the various individual and environmental predictors and adolescents alcohol use. CONCLUSIONS Alcohol expectancies form an important framework through which drinking behavior can be explained over time. Due to the diverse findings on the predictors of AE, future longitudinal studies should further clarify the factors that are essential in the development of AE and adolescents later alcohol use.

The effectiveness of a web-based brief alcohol intervention in reducing heavy drinking among adolescents aged 15 to 20 years with a low educational background: study protocol for a randomized controlled trial

BackgroundThe serious negative health consequences of heavy drinking among adolescents is cause for concern, especially among adolescents aged 15 to 20 years with a low educational background. In the Netherlands, there is a lack of alcohol prevention programs directed to the drinking patterns of this specific target group. The study described in this protocol will test the effectiveness of a web-based brief alcohol intervention that aims to reduce alcohol use among heavy drinking adolescents aged 15 to 20 years with a low educational background.Methods/designThe effectiveness of the What Do You Drink (WDYD) web-based brief alcohol intervention will be tested among 750 low-educated, heavy drinking adolescents. It will use a two-arm parallel group cluster randomized controlled trial. Classes of adolescents from educational institutions will be randomly assigned to either the experimental (n = 375: web-based brief alcohol intervention) or control condition (n = 375: no intervention). Primary outcomes measures will be: 1) the percentage of participants who drink within the normative limits of the Dutch National Health Council for low-risk drinking, 2) reductions in mean weekly alcohol consumption, and 3) frequency of binge drinking. The secondary outcome measures include the alcohol-related cognitions, attitudes, self-efficacy, and subjective norms, which will be measured at baseline and at one and six months after the intervention.DiscussionThis study protocol presents the study design of a two-arm parallel-group randomized controlled trial to evaluate the effectiveness of the WDYD web-based brief alcohol intervention. We hypothesized a reduction in mean weekly alcohol consumption and in the frequency of binge drinking in the experimental condition, resulting from the web-based brief alcohol intervention, compared to the control condition.Trial registrationNetherlands Trial Register NTR2971

Exposure to drinking mediates the association between parental alcohol use and preteen alcohol use

OBJECTIVE The aim of the present study was to test the link between exposure to parental alcohol use (i.e., preteens seeing their parents drinking) and preteens alcohol use. Specifically, this study aimed to (a) replicate the association between parental alcohol use and preteen alcohol use and (b) test whether alcohol use exposure mediated this association. METHOD Families were recruited from five regions in the Netherlands from 104 schools that agreed to participate. Preteens (N = 755, Mage = 11.27, SD = 0.56, 45.8% boys) and their mothers (N = 755) participated in the study. Preteens reported lifetime alcohol use and parental alcohol use exposure. Mothers reported on alcohol use for both parents. Structural Equation Modelling was used to assess direct and mediated paths between parental alcohol use, preteens exposure to alcohol use and preteen alcohol use in one model. RESULTS Unexpectedly, fathers alcohol use was negatively associated (β = -0.121, p = .012) and mothers alcohol use was not associated (β = 0.056, p = .215) with preteens alcohol use. A positive indirect effect emerged through alcohol use exposure, showing that exposure to fathers alcohol use mediated the association between parents and preteens alcohol use (β = 0.064, p = .001). This effect was absent for mothers alcohol use (β = 0.026, p = .264). Gender differences were non-significant. CONCLUSIONS Parental alcohol exposure positively mediated the association of parental alcohol use with preteens alcohol use. These effects were found for both boys and girls and were most robust for fathers drinking. The findings might provide clues for preventive action, for example, by emphasizing that exposure should be restricted to prevent preteens alcohol use.

The effectiveness of the What Do You Drink (WDYD) web-based brief alcohol intervention over time: a two-arm parallel group randomized controlled trial applying an ecological momentary assessment approach

The aim of the current study was to test whether the web-based brief alcohol intervention entitled “What Do You Drink” (WDYD) can sustain a reduction in alcohol use among heavy drinking students after one, three, and six months follow-up. A two-arm parallel group randomized controlled trial applying an ecological momentary assessment (EMA) approach with 30 data time-points was conducted in the Netherlands, 2010-2011. Students aged 18 to 24 years old who reported heavy drinking in the past six months and who were ready to change behaviour were included in the study. Participants were randomized into the experimental (n = 456: WDYD intervention) or control condition (n = 451: no intervention). Outcome measures were weekly alcohol consumption and frequency of binge drinking. Latent growth curve analyses to model individual change in alcohol use over time by condition revealed that participants in the experimental condition had significantly lower weekly alcohol consumption and frequency of binge drinking compared to participants in the control condition that sustained after three (B0 = -2.60, p < .001; B1 = 0.16, p = 0.08) and six (B0 = -0.14, p = 0.01; B1 = 0.00, p = 0.19) months follow-up, respectively. Additional linear regression analyses indicated that the intercept differences resulted from an increase in alcohol use for participants in the control condition compared to those in the experimental condition. The WDYD intervention was shown to be effective in preventing an increase in weekly alcohol consumption and frequency of binge drinking shortly after the intervention that sustained after three and six months post-intervention, respectively. Trial registration: Netherlands Trial Register NTR2665.