Ina M. Koning

Preventing heavy alcohol use in adolescents (PAS): cluster randomized trial of a parent and student intervention offered separately and simultaneously

AIMS To evaluate the effectiveness of two preventive interventions to reduce heavy drinking in first- and second-year high school students. DESIGN AND SETTING Cluster randomized controlled trial using four conditions for comparing two active interventions with a control group from 152 classes of 19 high schools in the Netherlands. PARTICIPANTS A total of 3490 first-year high school students (mean 12.68 years, SD=0.51) and their parents. Intervention conditions (i) Parent intervention (modelled on the Swedish Örebro Prevention Program) aimed at encouraging parental rule-setting concerning their childrens alcohol consumption; (ii) student intervention consisting of four digital lessons based on the principles of the theory of planned behaviour and social cognitive theory; (iii) interventions 1 and 2 combined; and (iv) the regular curriculum as control condition. Main outcome measures Incidence of (heavy) weekly alcohol use and frequency of monthly drinking at 10 and 22 months after baseline measurement. FINDINGS   A total of 2937 students were eligible for analyses in this study. At first follow-up, only the combined student-parent intervention showed substantial and statistically significant effects on heavy weekly drinking, weekly drinking and frequency of drinking. At second follow-up these results were replicated, except for the effects of the combined intervention on heavy weekly drinking. These findings were consistent across intention-to-treat and completers-only analyses. CONCLUSIONS Results suggest that adolescents as well as their parents should be targeted in order to delay the onset of drinking, preferably prior to onset of weekly drinking.

Alcohol-Specific Socialization Practices and Alcohol Use in Dutch Early Adolescents.

The present study examined the associations of alcohol-specific socialization practices and heavy parental drinking with alcohol use in early adolescents. Cross-sectional nationwide survey data from 2599 parent-adolescent (mean age=12.16) dyads were used to conduct logistic regression analyses. Onset of alcohol use as well as infrequent and regular drinking were associated with tolerant rules and attitude as reported by adolescents, and by a tolerant attitude as reported by parents. In contrast to former studies including middle and late adolescents, parental alcohol use was not found to be associated with early adolescent alcohol use, nor did parental alcohol use influence the impact of parental rules. Restrictive alcohol-specific socialization was, independent of parental alcohol use, related to absence of (regular) early adolescent drinking. Thus, this study demonstrated that in early adolescence alcohol-specific parenting is more important for adolescent drinking than parental alcohol use.

Long-Term Effects of a Parent and Student Intervention on Alcohol Use in Adolescents: A Cluster Randomized Controlled Trial

BACKGROUND Early onset of drinking among Dutch adolescents is highly prevalent. A lower age of onset is associated with several developmental and social risks. PURPOSE To evaluate the long-term effectiveness of two preventive interventions targeting heavy drinking in third-year high school students. DESIGN Cluster RCT using four conditions for comparing two active interventions (separately and simultaneously) with a control group. SETTING/PARTICIPANTS 152 classes of 19 high schools in the Netherlands; 3490 first-year high school students (M=12.6 years, SD=0.49) and their parents. INTERVENTION (1) parent intervention aimed at encouraging restrictive parental rule-setting concerning their childrens alcohol consumption; (2) student intervention aimed at increasing self-control and healthy attitudes toward alcohol, consisting of four digital lessons based on the principles of the theory of planned behavior and social cognitive theory; (3) interventions 1 and 2 combined; and (4) the regular curriculum as control condition. MAIN OUTCOME MEASURES Incidence of (heavy) weekly alcohol use at 34 months (2009) after baseline measurement (2006). RESULTS There were 2937 students eligible for analyses in this study. At follow-up, only the combined student-parent intervention showed substantial and significant effects on heavy weekly and weekly drinking. CONCLUSIONS The short-term effects found in the present study further support that adolescents as well as their parents should be targeted in order to delay the onset of (heavy) drinking. TRIAL REGISTRATION NTR649.

A comparison of self-reported alcohol use measures by early adolescents: Questionnaires versus diary

To examine the reliability of self-reports on prevalence, frequency and quantity of drinking in early adolescents by comparing questionnaires with diary reports. Retrospective data were obtained with a questionnaire after conducting a 1-month daily diary on alcohol use in a sample of 78 early adolescents. Sensitivity, specificity, positive, negative predictive values and correlations were calculated to test whether questionnaire reports corresponded with diary reports. Adolescents reported higher prevalence of drinking in diary reports than questionnaire reports. The sensitivity and negative predicted value of drinking prevalence were low, whereas the specificity and positive predicted value were high. Frequency of drinking reported in diary reports were highly correlated with questionnaire reports, whereas for the quantity of drinking only a moderate correlation was found. No significant differences were found for the average frequency and quantity of drinking between questionnaire and diary reports. Questionnaire reports tend to underestimate the prevalence of drinking in early adolescents compared to diary reports, whereas for frequency and quantity of drinking questionnaire reports proved to be reliable.

Differential Impact of a Dutch Alcohol Prevention Program Targeting Adolescents and Parents Separately and Simultaneously: Low Self-Control and Lenient Parenting at Baseline Predict Effectiveness

To test whether baseline levels of the factors accountable for the impact of the Prevention of Alcohol use in Students (PAS) intervention (self-control, perceived rules about alcohol and parental attitudes about alcohol), moderate the effect of the intervention. A cluster randomized trial including 3,490 Dutch early adolescents (M age = 12.66, SD = 0.49) and their parents randomized over four conditions: 1) parent intervention, 2) student intervention, 3) combined intervention and 4) control group. Moderators at baseline were used to examine the differential effects of the interventions on onset of (heavy) weekly drinking at 34-month follow-up. The combined intervention was only effective in preventing weekly drinking among those adolescents who reported to have lower self-control and more lenient parents at baseline. No differential effect was found for the onset of heavy weekly drinking. No moderating roles of self-control and lenient parenting were found for the separate student and parent interventions regarding the onset of drinking. The combined intervention is more effective among adolescents with low-self control and lenient parents at baseline, both factors that were a specific target of the intervention. The relevance of targeting self-control in adolescents and restrictive parenting is underlined.

Factors associated with traumatic symptoms and internalizing problems among adolescents who experienced a traumatic event

Abstract The aim of the present study was to identify factors that are related to the traumatic symptoms and problem behavior among adolescents who experienced the New Years fire in 2001 in Volendam, The Netherlands. Three groups of factors were considered: pre-trauma (personality and coping), trauma-related (physical and emotional proximity to disaster), and post-trauma factors (received social support). Forty-five adolescents completed the questionnaire. Two years after the disaster, these adolescents experienced significant traumatic stress reaction (70% within the clinical range) and showed clinically significant levels of internalizing problems (37%). Pre-trauma, individual factors were identified as the most important predictors of distress, followed by received social support. The indicators of physical and emotional proximity to disaster explained little variance in distress.

Risk moderation of a parent and student preventive alcohol intervention by adolescent and family factors: A cluster randomized trial

OBJECTIVE To examine risk moderation of an alcohol intervention targeting parents and adolescents. DESIGN A cluster randomized trial including 2937 Dutch early adolescents (m=12.68years, SD=0.51) and their parents randomized over four conditions: parent intervention, student intervention, combined parent-student intervention, and control group. SETTING 152 classes of 19 high schools in The Netherlands (2006). METHOD Moderators at baseline (adolescent: gender, educational level and externalizing behavior; parent: educational level and heavy alcohol use) were used to examine the differential effects of the interventions on onset of (heavy) weekly drinking at 22-month follow-up. RESULTS The combined intervention effectively delayed the onset of weekly drinking in the general population of adolescents, and was particularly effective in delaying the onset of heavy weekly drinking in a higher-risk subsample of adolescents (i.e. those attending lower levels of education and reporting higher levels of externalizing behavior). CONCLUSION Present and previous results have established the combined intervention to be universally effective in postponing weekly alcohol use among Dutch adolescents, with an added effect on postponing heavy weekly drinking in high risk subgroups. Therefore, implementation of this intervention in the general population of schools in The Netherlands is advised. TRIAL REGISTRATION NTR649.

An Experimental Study of Risk Taking Behavior Among Adolescents: A Closer Look at Peer and Sex Influences

In this experimental study, it was examined to what extent peers and sex were important predictors of risk taking behavior of adolescents. Participants were 140 Dutch adolescents (52.9% boys, 12-15 years) who completed the Balloon Analogue Risk Task (BART) as a measure of risk taking behavior, either individually or in the presence of homogenous or heterogeneous peer groups. Results showed that (a) adolescents took significantly more risk when they completed the BART with peers than when they completed the risk taking task individually, (b) boys took significantly more risk when they completed the task with peers than girls but not when they completed the task individually, and (c) boys in “boy-only triads” revealed the strongest risk taking behavior compared with “mixed-girl triads” or “girl-only triads.” These results suggest that boys appear to be more susceptible to the influence of peers on risk taking behavior than girls.

Causal Mediation Analysis With a Binary Outcome and Multiple Continuous or Ordinal Mediators: Simulations and Application to an Alcohol Intervention

We investigate a method to estimate the combined effect of multiple continuous/ordinal mediators on a binary outcome: (a) fit a structural equation model with probit link for the outcome and identity/probit link for continuous/ordinal mediators, (b) predict potential outcome probabilities, and (c) compute natural direct and indirect effects. Step 2 involves rescaling the latent continuous variable underlying the outcome to address residual mediator variance and covariance. We evaluate the estimation of risk-difference- and risk-ratio-based effects (RDs, RRs) using the maximum likelihood (ML), mean-and-variance-adjusted weighted least squares (WLSMV) and Bayes estimators in Mplus. Across most variations in path-coefficient and mediator-residual-correlation signs and strengths, and confounding situations investigated, the method performs well with all estimators, but favors ML/WLSMV for RDs with continuous mediators, and Bayes for RRs with ordinal mediators. Bayes outperforms ML/WLSMV regardless of mediator type when estimating RRs with small potential outcome probabilities and in two other special cases. An adolescent alcohol prevention study is used for illustration.

Climate schools plus: an online, combined student and parent, universal drug prevention program.

Early initiation of substance use significantly increases ones risk of developing substance use dependence and mental disorders later in life. To interrupt this trajectory, effective prevention during the adolescent period is critical. Parents play a key role in preventing substance use and related harms among adolescents and parenting interventions have been identified as critical components of effective prevention programs. Despite this, there is currently no substance use prevention program targeting both students and parents that adopts online delivery to overcome barriers to implementation and sustainability. The Climate Schools Plus (CSP) program was developed to meet this need. CSP is an online substance use prevention program for students and parents, based on the effective Climate Schools prevention program for students. This paper describes the development of the parent component of CSP including a literature review and results of a large scoping survey of parents of Australian high school students (n = 242). This paper also includes results of beta-testing of the developed program with relevant experts (n = 10), and parents of Australian high school students (n = 15). The CSP parent component consists of 1) a webinar which introduces shared rule ranking, 2) online modules and 3) summaries of student lessons. The parent program targets evidence-based modifiable factors associated with a delay in the onset of adolescent substance use and/or lower levels of adolescent substance use in the future; namely, rule-setting, monitoring, and modelling. To date, this is the first combined parent-student substance use prevention program to adopt an online delivery method.