Liesbeth Mercken

Challenges to the peer influence paradigm: results for 12–13 year olds from six European countries from the European Smoking Prevention Framework Approach study

Objective: To examine whether smoking onset in young adolescents is predicted by peer or parental smoking. Design: Longitudinal design with one pretest and one follow-up at 12 months. Setting: Schools in Finland, Denmark, the Netherlands, the United Kingdom, Spain and Portugal. Participants: 7102 randomly selected adolescents from six countries. Mean age was 12.78 years. Main outcome measures: Smoking behaviour of adolescents, peers and parents. Results: No support was found for peer smoking as an important predictor of smoking onset in most countries. Support was found for the selection paradigm, implying that adolescents choose friends with similar smoking behaviour. Support for the impact of parents on adolescent behaviour and the choice of friends was also found. Conclusions: Smoking uptake in this age cohort may be more strongly influenced by personal and parental influences than initially believed. Hence, social inoculation programmes teaching youngsters to resist the pressures to smoke may be less appropriate if youngsters have a positive attitude towards smoking, associate smoking with various advantages and look for peers with similar values. For this group attitudes towards smoking may thus guide future friend selection.

Dynamics of adolescent friendship networks and smoking behavior

The mutual influence of smoking behavior and friendships in adolescence is studied. It is attempted to disentangle influence and selection processes in reciprocal and non-reciprocal friendships. An actorbased model is described for the co-evolution of friendship networks and smoking behavior. This model considers alternative selection and influence mechanisms, and models continuous-time changes in network and behavior. The data consists of a longitudinal sample of 1326 Finnish adolescents in 11 high schools. Findings suggest that selection as well as influence processes play an important role in adolescent smoking behavior. Selection had a relatively stronger role than influence, in particular when selecting non-reciprocal friends. The strength of both influence and selection processes decreased over time.

Perceived support as a mediator of the relationship between justice and trust: A multiple foci approach

Using a sample of 212 employees, the authors examined the relationships between employees’ perceptions of procedural and interactional justice and their subsequent trust in their organization and supervisor. Specifically, the authors predicted that the link between procedural justice and trust in organization would be mediated by perceived organizational support (POS), whereas the relationship between interactional justice and trust in supervisor would be mediated by perceived supervisor support (PSS). In line with predictions, the authors found that POS partially mediated the effect of procedural justice on trust in organization and PSS partially mediated the impact of interactional justice on trust in supervisor. These findings suggest that employees develop relationships with their supervisors that are distinct from those relationships they experience with their organization.

Smoking-based selection and influence in gender-segregated friendship networks: a social network analysis of adolescent smoking

AIMS The main goal of this study was to examine differences between adolescent male and female friendship networks regarding smoking-based selection and influence processes using newly developed social network analysis methods that allow the current state of continuously changing friendship networks to act as a dynamic constraint for changes in smoking behaviour, while allowing current smoking behaviour to be simultaneously a dynamic constraint for changes in friendship networks. DESIGN Longitudinal design with four measurements. SETTING Nine junior high schools in Finland. PARTICIPANTS A total of 1163 adolescents (mean age = 13.6 years) who participated in the control group of the ESFA (European Smoking prevention Framework Approach) study, including 605 males and 558 females. MEASUREMENTS Smoking behaviour of adolescents, parents, siblings and friendship ties. FINDINGS Smoking-based selection of friends was found in male as well as female networks. However, support for influence among friends was found only in female networks. Furthermore, females and males were both influenced by parental smoking behaviour. CONCLUSIONS In Finnish adolescents, both male and female smokers tend to select other smokers as friends but it appears that only females are influenced to smoke by their peer group. This suggests that prevention campaigns targeting resisting peer pressure may be more effective in adolescent girls than boys.

Peer selection and influence effects on adolescent alcohol use: a stochastic actor-based model

BackgroundEarly adolescent alcohol use is a major public health challenge. Without clear guidance on the causal pathways between peers and alcohol use, adolescent alcohol interventions may be incomplete. The objective of this study is to disentangle selection and influence effects associated with the dynamic interplay of adolescent friendships and alcohol use.MethodsThe study analyzes data from Add Health, a longitudinal survey of seventh through eleventh grade U.S. students enrolled between 1995 and 1996. A stochastic actor-based model is used to model the co-evolution of alcohol use and friendship connections.ResultsSelection effects play a significant role in the creation of peer clusters with similar alcohol use. Friendship nominations between two students who shared the same alcohol use frequency were 3.60 (95% CI: 2.01-9.62) times more likely than between otherwise identical students with differing alcohol use frequency. The model controlled for alternative pathways to friendship nomination including reciprocity, transitivity, and similarities in age, gender, and race/ethnicity. The simulation model did not support a significant friends’ influence effect on alcohol behavior.ConclusionsThe findings suggest that peer selection plays a major role in alcohol use behavior among adolescent friends. Our simulation results would lend themselves to adolescent alcohol abuse interventions that leverage adolescent social network characteristics.

Are physical activity interventions equally effective in adolescents of low and high socio-economic status (SES): results from the European Teenage project

The aim was to study whether physical activity (PA) interventions in European teenagers are equally effective in adolescents of low versus high socio-economic status (SES). Based on a systematic review (Project TEENAGE), three school-based studies for secondary analyses were selected. SES stratified analyses were run in: (i) a Belgian multi-component intervention, (ii) a French multi-component intervention and (iii) a Belgian computer-tailored education trial. Results of the secondary analyses showed that no overall significant differences between low and high SES groups were found, but some interesting specific effects were revealed. Results from the first study showed an increase in objective PA in the low SES group (P = 0.015) compared with no significant effects in the high SES group. In the second study, larger effects were found in adolescents of high SES (increase of 11 min day(-1) P < 0.001), compared with adolescents of lower SES (increase of 7 min day(-1), P = 0.02) at the longer term. The third study showed a positive effect on school-related PA in adolescents of high SES (P < 0.05) and on leisure time transportation in adolescents of low SES (P < 0.05). To conclude, we were not able to show a significant widening or narrowing of inequalities in European adolescents.

Predicting parental sunscreen use: Disentangling the role of action planning in the intention–behavior relationship

Structural equation modeling was used to examine antecedents of parental sunscreen use (N = 436) in a longitudinal design. The influence of a volitional planning cognition was assessed in several path models, investigating potential mediation and moderation of the intention–behavior relationship. Premotivational and motivational variables accounted for 55.1% of the variance in intention to use sunscreen. Intention emerged as the most powerful predictor of behavior, followed by action planning and self-efficacy expectations, together explaining 35.4% of parental sunscreen use after five months. Strong support was found for both mediating and moderating influences of action planning on the intention–behavior relationship. Action planning also partially mediated the impact of self-efficacy on behavior. The results support theoretical considerations to add postintentional cognitions to current health behavior models. Although action planning is an important component in the transition from intention to behavior, the impact of intention and of other premotivational and motivational variables should not be overlooked when developing health educational interventions.

A web-based computer-tailored smoking prevention programme for primary school children: intervention design and study protocol

BackgroundAlthough the number of smokers has declined in the last decade, smoking is still a major health problem among youngsters and adolescents. For this reason, there is a need for effective smoking prevention programmes targeting primary school children. A web-based computer-tailored feedback programme may be an effective intervention to stimulate youngsters not to start smoking, and increase their knowledge about the adverse effects of smoking and their attitudes and self-efficacy regarding non-smoking.Methods & designThis paper describes the development and evaluation protocol of a web-based out-of-school smoking prevention programme for primary school children (age 10-13 years) entitled ‘Fun without Smokes’. It is a transformation of a postal mailed intervention to a web-based intervention. Besides this transformation the effects of prompts will be examined. This web-based intervention will be evaluated in a 2-year cluster randomised controlled trial (c-RCT) with three study arms. An intervention and intervention + prompt condition will be evaluated for effects on smoking behaviour, compared with a no information control condition. Information about pupils’ smoking status and other factors related to smoking will be obtained using a web-based questionnaire. After completing the questionnaire pupils in both intervention conditions will receive three computer-tailored feedback letters in their personal e-mail box. Attitudes, social influences and self-efficacy expectations will be the content of these personalised feedback letters. Pupils in the intervention + prompt condition will - in addition to the personalised feedback letters - receive e-mail and SMS messages prompting them to revisit the ‘Fun without Smokes’ website. The main outcome measures will be ever smoking and the utilisation of the ‘Fun without Smokes’ website. Measurements will be carried out at baseline, 12 months and 24 months of follow-up.DiscussionThe present study protocol describes the purpose, intervention design and study protocol of ‘Fun without Smokes’. Expectations are that pupils receiving tailored advice will be less likely to smoke after 24 months in contrast to pupils in the control condition. Furthermore, tailored feedback letters and prompting is expected to be more effective than providing tailored feedback letters only.Trial registrationDutch Trial Register NTR3116

A sexual affiliation network of swingers, heterosexuals practicing risk behaviours that potentiate the spread of sexually transmitted infections: A two-mode approach

Abstract Using the example of the sexual affiliation networks of swingers, this paper examines how the analysis of sexual affiliation networks can contribute to the development of sexually transmitted infection (STI) prevention strategies. Two-mode network methodology and ERGMs are applied to describe the structural composition of the affiliation network and analyse attribute effects. Swingers were found to recruit their sex partners through one large, moderately cohesive network component. Swingers who used drugs or had a longer history of swinging tended to frequent websites instead of clubs. This study confirms the relevance of studying sexual affiliation networks and its additional value for STI epidemiology.

The effectiveness of school-based smoking prevention interventions among low- and high-SES European teenagers

Preventing smoking initiation among adolescents of lower socio-economic groups is crucial for the reduction of socio-economic inequalities in health. The aim of the present study was to examine whether effective smoking prevention interventions in Europe are equally effective among adolescents of low- and high-socio-economic status (SES). As part of the European Union-funded TEENAGE project, three school-based smoking prevention intervention studies in Europe were selected for secondary analyses: (i) a Dutch class competition intervention, (ii) the European Smoking Prevention Framework (ESFA) study and (iii) the A Stop Smoking in Schools Trial (ASSIST) intervention. All three studies differed in effectiveness by SES. The Dutch class competition study only had a significant effect among higher SES adolescents. The results for the ESFA study and ASSIST study were mixed and depended on which SES indicator was used. The conclusion of the study is that stratified analyses provide important insights in differential intervention effects for higher and lower socio-economic groups. Although findings from the different studies were mixed, interventions that use a social network approach in which youngsters are allowed to deliver the intervention themselves may be a successful strategy in targeting adolescents from lower socio-economic groups.