How to foster informed decision making about food supplements: results from an international Delphi study.

Food supplement use can have beneficial and detrimental effects, making informed decisions about supplement use important. How these decisions are made and which communication strategies can stimulate informed decision making is unclear. This study identified the important characteristics of (i) informed decision making about food supplement use and (ii) important factors indicating how to communicate about food supplements to foster informed decision making. An online three-round Delphi study was conducted. International experts within the field of (risk) communication about food supplements or related fields were recruited via email. The participants' age ranged from 25 to 69 years, and sample sizes for the three rounds were 38, 89 and 51, respectively. Experts indicated that for making an informed decision about food supplement use one needs to have knowledge of their positive and negative effects, the ability to compare these effects, knowing alternatives besides supplements, feeling informed, and feeling able (self-efficacious) to make the decision and making the decision voluntarily. Important communication strategies mentioned were: provision of information about positive and negative effects and the nature of these effects including scientific evidence, ensuring information is easily accessible, well ordered, tailored and provided by a trustworthy, credible and independent source.

Predicting Primary and Secondary Abstinence Among Adolescent Boys and Girls in the Western Cape, South Africa.

Two of the most effective health behaviours with regard to HIV prevention are condom use and sexual abstinence. While determinants of condom use among sub-Saharan African adolescents have been studied extensively, factors related to abstinence have received far less attention. This study identified socio-cognitive determinants of primary and secondary abstinence intentions and of early sexual activity. This study also assessed whether these factors had a direct or indirect association with intentions to abstain from sex. A longitudinal design was used in which 1670 students (age 12-16) of non-private South African high schools filled in a questionnaire, with a follow-up after 6 months, concerning sexual abstinence, attitudes, social norms, self-efficacy, risk perception and knowledge. Logistic and linear regression analysis with latent factors was used to assess determinants of intentions and abstinence, and structural equation modelling was used to assess indirect effects. Results showed that among sexually inactive students, social norms predicted the intention to abstain from sex in the next 6 months. Among sexually active students, reporting less disadvantages of abstinence predicted the intention to abstain. Sexual activity at follow-up was predicted by attitudes and intention among sexually inactive girls, and by knowledge among sexually inactive boys. No predictors were found for sexually active adolescents. Structural equation modelling further showed that risk perception was indirectly related to intentions to abstain from sexual intercourse. We conclude that addressing socio-cognitive factors in order to motivate adolescents to delay sex is more likely to be successful before they experience sexual debut. In addition, this study shows that the effect of increasing risk perceptions, a strategy often applied by parents and HIV prevention programmes, is to a large extent mediated by more proximal cognitive factors such as attitude. Research is needed to identify factors that influence the execution of intentions to abstain from sex.

Effects of PREPARE, a Multi-component, School-Based HIV and Intimate Partner Violence (IPV) Prevention Programme on Adolescent Sexual Risk Behaviour and IPV: Cluster Randomised Controlled Trial.

Young South Africans, especially women, are at high risk of HIV. We evaluated the effects of PREPARE, a multi-component, school-based HIV prevention intervention to delay sexual debut, increase condom use and decrease intimate partner violence (IPV) among young adolescents. We conducted a cluster RCT among Grade eights in 42 high schools. The intervention comprised education sessions, a school health service and a school sexual violence prevention programme. Participants completed questionnaires at baseline, 6 and 12 months. Regression was undertaken to provide ORs or coefficients adjusted for clustering. Of 6244 sampled adolescents, 55.3 % participated. At 12 months there were no differences between intervention and control arms in sexual risk behaviours. Participants in the intervention arm were less likely to report IPV victimisation (35.1 vs. 40.9 %; OR 0.77, 95 % CI 0.61-0.99; t(40) = 2.14) suggesting the intervention shaped intimate partnerships into safer ones, potentially lowering the risk for HIV.

Sociocognitive Predictors of Condom Use and Intentions Among Adolescents in Three Sub-Saharan Sites.

Many HIV intervention programs in sub-Saharan Africa have applied social cognitive theories such as the theory of planned behavior. However, a recent sub-Saharan African review was unable to show increased effectiveness for theory-based interventions. This study assessed whether the predictive value of attitudes, subjective norms, self-efficacy, and intention was similar to studies in Europe and the U.S., and whether there were differences between three sub-Saharan sites. Longitudinal multigroup structural equation modeling was used to assess whether attitudes, subjective norms, and self-efficacy predicted condom use intentions and condom use (after 6 months) among adolescents in three sites, namely Cape Town (South Africa; N = 625), Dar es Salaam (Tanzania; N = 271), and Mankweng (South Africa; N = 404). Condom use intentions were predicted by subjective norms and self-efficacy in all three sites. Attitudes were not related to intentions in Dar es Salaam and were moderately related to intentions in Cape Town and Mankweng. The proportions of explained variance in intentions and behavior were decent (37-52 and 9-19%, respectively). Although significant differences in predictive value were found between sites and in comparison to European and U.S. studies, intentions could adequately be explained by attitudes, subjective norms, and self-efficacy. However, the limited proportions of variance in behavior explained by intentions could signify the importance of contextual and environmental factors. Future studies are recommended to use an integrative approach that takes into account both individual and contextual factors, as well as social and environmental differences.

Predicting safe sex: Assessment of autoregressive and cross-lagged effects within the Theory of Planned Behavior.

Despite its popularity, few studies have assessed the temporal stability and cross-lagged effects of the Theory of Planned Behavior factors: Attitude, subjective norms and self-efficacy. For this study, 298 adolescent learners from KwaZulu-Natal, South Africa, filled out a Theory of Planned Behavior questionnaire on teenage pregnancy at baseline and after 6 months. Structural equation modeling showed that there were considerable cross-lagged effects between attitude and subjective norms. Temporal stability was moderate with test-retest correlations ranging from 0.37 to 0.51 and the model was able to predict intentions to have safe sex (R2 = 0.69) Implications for practice and future research are discussed.

Predicting fruit consumption: the role of habits, previous behavior and mediation effects.

BACKGROUND: This study assessed the role of habits and previous behavior in predicting fruit consumption as well as their additional predictive contribution besides socio-demographic and motivational factors. In the literature, habits are proposed as a stable construct that needs to be controlled for in longitudinal analyses that predict behavior. The aim of this study is to provide empirical evidence for the inclusion of either previous behavior or habits. METHODS: A random sample of 806 Dutch adults (>18 years) was invited by an online survey panel of a private research company to participate in an online study on fruit consumption. A longitudinal design (N = 574) was used with assessments at baseline and after one (T2) and two months (T3). Multivariate linear regression analysis was used to assess the differential value of habit and previous behavior in the prediction of fruit consumption. RESULTS: Eighty percent of habit strength could be explained by habit strength one month earlier, and 64% of fruit consumption could be explained by fruit consumption one month earlier. Regression analyses revealed that the model with motivational constructs explained 41% of the behavioral variance at T2 and 38% at T3. The addition of previous behavior and habit increased the explained variance up to 66% at T2 and to 59% at T3. Inclusion of these factors resulted in non-significant contributions of the motivational constructs. Furthermore, our findings showed that the effect of habit strength on future behavior was to a large extent mediated by previous behavior. CONCLUSIONS: Both habit and previous behavior are important as predictors of future behavior, and as educational objectives for behavior change programs. Our results revealed less stability for the constructs over time than expected. Habit strength was to a large extent mediated by previous behavior and our results do not strongly suggest a need for the inclusion of both constructs. Future research needs to assess the conditions that determine direct influences of both previous behavior and habit, since these influences may differ per type of health behavior, per context stability in which the behavior is performed, and per time frame used for predicting future behavior.

Predicting condom use in South Africa: a test of two integrative models.

This study tested two integrative socio-cognitive models, namely the information-motivation-behavioral skills model (IMB) and the I-Change model (ICM), to assess their hypothesized motivational pathways for the prediction of condom use during last sexual intercourse. Students (N = 1066) from Cape Town, South Africa, filled out questionnaires at three different time points. Structural equation modeling demonstrated that self-efficacy did not predict behavior directly but indirectly via intention. Knowledge of how to use a condom and how STIs are transmitted directly predicted behavior when modeled as hypothesized by the IMB model, but indirectly when the factors attitude, subjective norms and self-efficacy were included as mediators, as hypothesized by the ICM. It is concluded that the ICM and IMB are similar in terms of model fit and explained variance, but that the ICM had a higher proportion of significant pathways.

The role of action planning and plan enactment for smoking cessation.

BACKGROUND: Several studies have reemphasized the role of action planning. Yet, little attention has been paid to the role of plan enactment. This study assesses the determinants and the effects of action planning and plan enactment on smoking cessation. METHODS: One thousand and five participants completed questionnaires at baseline and at follow-ups after one and six months. Factors queried were part of the I-Change model. Descriptive analyses were used to assess which plans were enacted the most. Multivariate linear regression analyses were used to assess whether the intention to quit smoking predicted action planning and plan enactment, and to assess which factors would predict quitting behavior. Subsequently, both multivariate and univariate regression analyses were used to assess which particular action plans would be most effective in predicting quitting behavior. Similar analyses were performed among a subsample of smokers prepared to quit within one month. RESULTS: Smokers who intended to quit smoking within the next month had higher levels of action planning than those intending to quit within a year. Additional predictors of action planning were being older, being female, having relatively low levels of cigarette dependence, perceiving more positive and negative consequences of quitting, and having high self-efficacy toward quitting. Plan enactment was predicted by baseline intention to quit and levels of action planning. Regression analysis revealed that smoking cessation after six months was predicted by low levels of depression, having a non-smoking partner, the intention to quit within the next month, and plan enactment. Only 29% of the smokers who executed relatively few plans had quit smoking versus 59% of the smokers who executed many plans. The most effective preparatory plans for smoking cessation were removing all tobacco products from the house and choosing a specific date to quit. CONCLUSION: Making preparatory plans to quit smoking is important because it also predicts plan enactment, which is predictive of smoking cessation. Not all action plans were found to be predictive of smoking cessation. The effects of planning were not very much different between the total sample and smokers prepared to quit within one month.