Rik Crutzen

Everything should be as simple as possible, but no simpler: towards a protocol for accumulating evidence regarding the active content of health behaviour change interventions

There is a need to consolidate the evidence base underlying our toolbox of methods of behaviour change. Recent efforts to this effect have conducted meta-regressions on evaluations of behaviour change interventions, deriving each methods effectiveness from its association to intervention effect size. However, there are a range of issues that raise concern about whether this approach is actually furthering or instead obstructing the advancement of health psychology theories and the quality of health behaviour change interventions. Using examples from theory, the literature and data from previous meta-analyses, these concerns and their implications are explained and illustrated. An iterative protocol for evidence base accumulation is proposed that integrates evidence derived from both experimental and applied behaviour change research, and combines theory development in experimental settings with theory testing in applied real-life settings. As evidence gathered in this manner accumulates, a cumulative science of behaviour change can develop.

An Exploration of Factors Related to Dissemination of and Exposure to Internet-Delivered Behavior Change Interventions Aimed at Adults: A Delphi Study Approach

Background The Internet is an attractive medium for delivering individualized, computer-tailored behavior change interventions to large numbers of people. However, the actual numbers of people reached seem to fall behind the high expectations. Insight into factors that determine use of and exposure to these Internet interventions is important to be able to increase the reach and improve exposure. Objective The aim was to identify potentially important factors that determine whether adults visit an Internet-delivered behavior change intervention, extend their visit, and revisit the intervention. Methods A systematic, three-round Delphi study was conducted among national and international experts from Internet intervention research and practice, e-marketing/e-commerce, Web design, and technical website development. In the first round, 30 experts completed a structured, open-ended online questionnaire assessing factors that were, in their opinion, important for a first visit, an extended visit, a revisit and for effective promotion strategies. Based on the responses in this first questionnaire, a closed-ended online questionnaire was developed for use in the second round. A total of 233 experts were invited to complete this questionnaire. Median and interquartile deviation (IQD) scores were computed to calculate agreement and consensus on the importance of the factors. The factors for which no consensus was obtained (IQD > 1) were included in the third-round questionnaire. Factors with a median score of six or higher and with an IQD ≤ 1 were considered to be important. Results Of the 62 experts invited for the first round, 30 completed the questionnaire (48% response rate); 93/233 experts completed the second-round questionnaire (40% response rate), and 59/88 completed the third round (67% response rate). Being motivated to visit an Internet intervention and perceiving the intervention as personally relevant appeared to be important factors related to a first visit. The provision of tailored feedback, relevant and reliable information, and an easy navigation structure were related to an extended visit. Provision of regular new content and the possibility to monitor personal progress toward behavior change were identified as important factors to encourage a revisit. Primarily traditional promotion strategies, like word-of-mouth by family and friends, a publicity campaign with simultaneous use of various mass media, and recommendation by health professionals, were indicated as effective ways to encourage adults to visit an Internet intervention. Conclusions This systematic study identified important factors related to the dissemination of and exposure to Internet interventions aimed at adults. In order to improve optimal use of and exposure to Internet interventions, potential users may need to be motivated to visit such an intervention and the information provided needs to be personally relevant. Furthermore, several (technical) aspects of the intervention itself need to be taken into account when developing Internet interventions.

Internet-delivered interventions aimed at adolescents: a Delphi study on dissemination and exposure

It appears that in practice exposure to Internet-delivered behaviour change interventions, encouraging a healthy lifestyle for adolescents with regard to health risk behaviours, is quite low. There is, however, a lack of evidence-based insight into how to disseminate such interventions and how to reach optimal exposure. A more extensive exploration is therefore timely since this knowledge is crucial to improve the public health impact of such interventions. By means of a three-round Delphi study factors associated with dissemination of and exposure (first visit, stay long enough and revisit) to Internet-delivered interventions aimed at adolescents had been identified, as well as the extent to which experts agree on the importance of these factors. Results showed that there was a high rate of consensus among experts from several disciplines with regard to the importance of factors like word of mouth recommendation, the interface of the intervention and utilization of all features provided by the Internet. Experts do not agree, however, on a gold standard for successful dissemination. Overall, the results of this exploration serve as a handle for the formation of further research questions to be tested and answered in research among adolescents.

Investigating Predictors of Visiting, Using, and Revisiting an Online Health-Communication Program: A Longitudinal Study

Background Online health communication has the potential to reach large audiences, with the additional advantages that it can be operational at all times and that the costs per visitor are low. Furthermore, research shows that Internet-delivered interventions can be effective in changing health behaviors. However, exposure to Internet-delivered health-communication programs is generally low. Research investigating predictors of exposure is needed to be able to effectively disseminate online interventions. Objective In the present study, the authors used a longitudinal design with the aim of identifying demographic, psychological, and behavioral predictors of visiting, using, and revisiting an online program promoting physical activity in the general population. Methods A webpage was created providing the public with information about health and healthy behavior. The website included a “physical activity check,” which consisted of a physical activity computer-tailoring expert system where visitors could check whether their physical activity levels were in line with recommendations. Visitors who consented to participate in the present study (n = 489) filled in a questionnaire that assessed demographics, mode of recruitment, current physical activity levels, and health motivation. Immediately after, participants received tailored feedback concerning their current physical activity levels and completed a questionnaire assessing affective and cognitive user experience, attitude toward being sufficiently physically active, and intention to be sufficiently physically active. Three months later, participants received an email inviting them once more to check whether their physical activity level had changed. Results Analyses of visiting showed that more women (67.5%) than men (32.5%) visited the program. With regard to continued use, native Dutch participants (odds ratio [OR] = 2.81, 95% confidence interval [CI] = 1.16-6.81, P = .02) and participants with a strong motivation to be healthy (OR = 1.46, CI = 1.03-2.07, P = .03) were most likely to continue usage of the program. With regard to revisiting, older participants (OR = 1.04, CI = 1.01-1.06, P = .01) and highly educated participants (OR = 4.69, CI = 1.44-15.22, P = .01) were more likely to revisit the program after three months. In addition, positive affective user experience predicted revisiting (OR = 1.64, CI = 1.12-2.39, P = .01). Conclusions The results suggest that online interventions could specifically target men, young people, immigrant groups, people with a low education, and people with a weak health motivation to increase exposure to these interventions. Furthermore, eliciting positive feelings in visitors may contribute to higher usage rates.

A conceptual framework for understanding and improving adolescents' exposure to Internet-delivered interventions

Although exposure is crucial to improve the public health impact of Internet-delivered interventions, it appears that in practice exposure to such interventions is low. Therefore, a conceptual framework, which incorporates elements of user experience of websites, is applied to Internet-delivered health behaviour change interventions aimed at adolescents and results from previous explorative research are incorporated. This framework, described from the point of view of an interventions development team, can be used in practice to optimize user experience and therewith improving exposure rates to Internet-delivered interventions and increasing the number of revisiting users.

Increasing fruit and vegetable intake among children: comparing long-term effects of a free distribution and a multicomponent program

The aim of this study was to evaluate and compare the effectiveness of two primary school-based interventions on childrens fruit and vegetable (F&V) consumption on the long term (2 years after the start of the interventions). Six primary schools were recruited and randomly assigned to (i) a daily free distribution program for the whole school or (ii) a multicomponent program consisting of a classroom curriculum and parental involvement (without free F&V), and six schools served as controls. Follow-up measurements were conducted at the end of the intervention (Follow-up I) and 1 year later (Follow-up II). Random coefficient analyses for longitudinal data showed that the effects of both interventions did not differ between the two follow-up measurements. The results showed similar effects for the free distribution program and the multicomponent program in increasing childrens fruit consumption over time (respectively, 7.2 and 15.2 g day(-1)). The distribution program also increased childrens vegetable consumption over time (3.25 g day(-1)), even after repeating the analyses using a pessimistic scenario. Despite the large dropout and its consequences for generalizability of our results, the distribution program is considered as the preferred intervention of the two, and implementation on a larger scale should be investigated.

Scale quality: alpha is an inadequate estimate and factor-analytic evidence is needed first of all

ABSTRACT Cronbachs alpha is a commonly reported estimate to assess scale quality in health psychology and related disciplines. In this paper, we argue that alpha is an inadequate estimate for both validity and reliability – two key elements of scale quality. Omega is a readily available alternative that can be used for both interval and ordinal data. More importantly, we argue that factor-analytic evidence should be presented before assessing the internal structure of a scale. Finally, pointers for readers and reviewers of manuscripts on making judgements about scale quality are provided and illustrated by examples from the field of health psychology.

A simple formula for the calculation of sample size in pilot studies

One of the goals of a pilot study is to identify unforeseen problems, such as ambiguous inclusion or exclusion criteria or misinterpretations of questionnaire items. Although sample size calculation methods for pilot studies have been proposed, none of them are directed at the goal of problem detection. In this article, we present a simple formula to calculate the sample size needed to be able to identify, with a chosen level of confidence, problems that may arise with a given probability. If a problem exists with 5% probability in a potential study participant, the problem will almost certainly be identified (with 95% confidence) in a pilot study including 59 participants.

Effectiveness of online word of mouth on exposure to an Internet-delivered intervention

The use of online word of mouth (WOM) seems a promising strategy to motivate young people to visit Internet-delivered interventions. An Internet-delivered intervention aimed at changing implicit attitudes related to alcohol was used in two experiments to test effectiveness of e-mail invitations on a first visit to the intervention. The results of the first experiment (N = 196) showed that an invitation by e-mail from a friend was more effective to attract young adults (aged 18–24 years) to the intervention website than an invitation from an institution. A 2 × 2 design was used in the second experiment (N = 236) to test manipulations of argument strength and the use of peripheral cues in invitations. Results showed that weak arguments were more effective to attract young adults to the intervention website when an incentive was withheld. These results need to be taken into account when using online WOM as a strategy to improve exposure to Internet-delivered interventions.

Adolescents' views about an internet platform for adolescents with mental health problems

– The purpose of this paper is to examine the needs and views of adolescents regarding the development of online support for mental health problems., – Semi‐structured qualitative focus group interviews were conducted with ten groups of Dutch adolescents (n=106), aged 12‐19 years, from four urban secondary schools offering different levels of education in the Southeastern part of The Netherlands. Interviews were verbally transcribed and analysed with Nvivo, using a classification based on the research questions., – The participants reported that they searched on the internet to get information or help for some mental health problems. They also expressed the need for a youth healthcare website offering information, self‐tests and anonymous help. They had different ideas about the layout of such a website, which were related to their educational level. Reliability of such a website was an important issue., – Adolescents reported a distinct need for online information and help for mental health problems. Youth healthcare organisations could meet this need by creating an innovative additional assistance method. These organisations should cooperate with website developers, taking into account that adolescents with different levels of education have different preferences regarding the interventions for online information and help., – This paper provides a conclusive examination of the needs and views of adolescents regarding development of online support for mental health problems.