The effectiveness of a web-based Dutch parenting program to prevent overweight in children 9–13 years of age: study protocol for a two-armed cluster randomized controlled trial

The aim of the “Scoring for Health” program is to increase the awareness of primary school students (and their parents) regarding the importance of engaging in a healthy lifestyle. The program runs for 20 weeks and begins and ends with a sports clinic at a nearby semi-professional soccer club.

Eleven primary schools in the Nijmegen region in the Netherlands were participating in the intervention program “Scoring for Health”; the principals of these 11 schools were asked to participate in our study. We asked the principals’ permission to distribute envelopes to the parents of the children in the participating schools. The envelopes contained an invitation letter in which we asked parents to participate with their child in our study. In addition, the envelopes contained information regarding the study (including the purpose of the study, length of the study, frequency of measurements, eligibility criteria, confidentially of the data, etc.), a passive informed consent form for the parent, a passive informed consent form for the child, and an envelope for returning the forms. Two weeks after distributing the invitation letters, we visited all of the school classes. In our presence, the children completed the baseline questionnaire in class; the children were able to ask questions if they encountered ambiguities when completing the questionnaire. Thereafter, we distributed envelopes to the parents; this second envelope included the parental baseline questionnaire, a letter in which we asked the parents to complete the baseline questionnaire, and an envelope for returning the questionnaire. Non-responders received a reminder after three weeks. Our goal was to recruit 322 parent–child dyads.

After baseline measurements were collected, an independent researcher at the Behavioral Science Institute randomly assigned all participating school classes to either the intervention group or the control group. Randomization was performed centrally at the school grade level class and within schools (to control for school characteristics) using a computerized random number generator with a blocked randomization scheme (block size was 2); the groups were stratified by ethnicity.

If more than one child living in the same household participated in the study, all participating children in that household were assigned to the same group as the oldest participating child in order to avoid contamination between groups.

Sample size was calculated based on the difference between the intervention group and the control group in terms of the following outcomes: improvement in healthy eating and a reduction in sedentary behavior in children in accordance with Dutch standards. Because the e-learning program has not been tested previously with respect to effectiveness, it is difficult to estimate an effect size. However, based on the outcomes of similar effectiveness studies and school-based programs in children 9–13 years of age [16-19], we expect a minimum difference of 20% between the control and intervention groups 12 months after baseline in the children’s dietary and/or sedentary behavior in accordance with the Dutch standards.

Based on data obtained from the Community Health Service in Nijmegen, 40% of children 9–13 years of age meet the daily standards for eating fruits and vegetables, minimizing sugar-sweetened beverages, playing outside or minimizing sedentary behavior [20]. Using a two-sided test with alpha = 0.05 and a power of 0.80, and taking into account the clustering of children within classes (with an estimated ICC of 0.05 and an average cluster size of 14), we calculated that we needed 161 children in each group (i.e., the intervention and control groups) in order to detect an increase of 20% in the number of children who meet the Dutch standard with respect to dietary or sedentary behavior, given an initial compliance rate of 40% (i.e., an increase from 40% to 60%).

The e-learning program “Making a healthy deal with your child” is based on the existing e-learning program “Talking with your child” [21], which is based on state-of-the-art knowledge regarding effective substance use–specific parenting [22], and the face-to-face parent-training program “Parents and children talking together”, which is designed to support parents with adolescent children with respect to their communication and conflict resolution skills [23-26]. The contents of “Talking with your child” are based on theoretical insights obtained from “Parent effectiveness training” [27] and “Parent management training – the Oregon model” [28]. Both of these programs are designed to build family relationships that are characterized by i) acceptance and non-judgmental attitudes towards each other, and ii) genuineness and being honest with respect to expressing feelings.

Using a six-step model, our program shows parents how to improve their communication and problem-solving skills. We transformed the original four-step model [26] into a six-step model by dividing the first step of the original four-step model (“discussing the problem and focusing on attentive and active listening, combined with giving opinions in ways that are most efficient and least intrusive for the child”) into three steps. The first step of our six-step model is “selecting a good time to discuss the problem”. The second step is “discussing the problem, combined with giving opinions in ways that are most efficient and least intrusive for the child”. The third step is “focusing on attentive and active listening”. The fourth step is “thinking of possible solutions for arguments between the parents and their child”; in this step, emphasis is placed upon brainstorming and giving all family members the opportunity to come up with solutions without judging or criticizing each other’s ideas. The fifth and sixth steps are “deciding on a solution to the particular argument” and “evaluating the chosen solution”, respectively.

For the theoretical knowledge regarding dietary, sedentary, and physically active behaviors, we used the guidelines of the Dutch Nutrition Center [29] and the Dutch Norm for Healthy Physical Activity [30], which were also used in the YHC.

The aim of our e-learning program entitled “Making a healthy deal with your child” is to strengthen the general and specific parenting styles and practices in existing interventions for preventing overweight in children. At the start of creating this e-learning program, a pilot study was conducted with four focus groups in order to gain more insight into—and to obtain specific examples of—difficult daily life situations in which mothers in low-SES neighborhoods experience difficulties encouraging healthy eating habits and physical activity in their school-age children. The mothers in these focus groups were of Dutch, Turkish, and Moroccan descent and had at least one child 8–13 years of age.

In the study group sessions, the five most commonly mentioned difficult situations were as follows: i) the daily struggle at the dining table (children do not want to eat their vegetables); ii) the child’s continuous desire for candy and snacks; iii) children having insufficient time in the morning to eat breakfast; iv) children spending an excessive amount of time using the computer and/or watching television; and v) children not wanting to turn off their computer game when asked to do so.

Another important finding of the pilot study was that mothers in low-SES neighborhoods indicated that they experience several difficulties with respect to parenting. The most commonly mentioned issues were attempting to establish rules and not being strict and/or consistent when rules are established. The results of this pilot study were used as the input for developing our e-learning program. Our e-learning program consists of five 30-minute episodes that are based on the five abovementioned difficult daily life situations. Each episode consists of video fragments in which “good” and “less good” ways of communicating with a child are shown, the six-step problem-solving model, practical and theoretical assignments, and feedback. Using this approach, parents receive tools that they can use to encourage their child to develop a healthy diet, to be less sedentary, and to be regularly physically active in everyday situations; these tools use both general and specific parenting and conflict-management approaches. Using this e-learning program, our goal was to create a short, flexible program that is both simple and attractive to parents from a variety of demographic backgrounds. Parents can follow the program in their own home, at a time that suits them best. The total time required to complete the e-learning program is approximately 150 minutes.

Each parent who was assigned to the intervention group received a personal login code, which they used to start the e-learning program. Over a course of ten weeks, the parents were allowed to complete the e-learning program at their own pace. After finishing each episode, the parents received an e-mail to thank them for finishing the episode and to encourage them to complete the next episode.

We measured the effect of the e-learning program on energy balance–related behaviors in the children and on the parenting skills and parental self-efficacy in the parents.

The following primary outcomes were measured: changes in the child’s dietary, sedentary, and physically active behaviors from baseline to the 5-month and 12-month follow-up visits. According to Dutch standards [15,29,30], healthy energy balance–related behaviors in children include i) eating breakfast daily; ii) eating at least two portions of fruit daily; iii) eating vegetables daily; iv) drinking less than two glasses of sugar-sweetened beverages daily; v) less than two hours of screen time (watching television and/or using the computer) each day; vi) playing outside for at least one hour each day; and vii) participating in an organized sport for ≥30 minutes at least twice a week.

The following secondary outcomes were measured: parental styles, parenting practices, and parental self-efficacy. In addition, we monitored the parents’ willingness to follow the e-learning program and the parents’ satisfaction with the e-learning program.

Parents and children were asked to complete a baseline questionnaire and again at the end of the “Scoring for Health” intervention program (5 and 12 months after the baseline assessment). The questionnaires for the children were administered in their respective schools, and the parents completed their questionnaires at home. The questionnaires were developed using existing validated Dutch questionnaires (or questionnaires that were used in currently ongoing projects within the Netherlands if no validated questionnaire was available). The questionnaires were designed to assess the following variables:

The parents’ login activity in the e-learning program was monitored during the intervention period. This allowed us to monitor which parents began the e-learning program (and which did not). This approach also provided information regarding which episodes the parents completed.

Anthropometric characteristics of the children (height and weight) were measured at baseline at the start of the “Scoring for Health program using a calibrated scale and measuring tape of the YHC in accordance with established guidelines [38]. All measurements were performed by a YHC professional or trainee. The child’s height was measured (while barefoot) to the nearest 0.1 cm using a model 208 body meter (SECA, Hamburg, Germany). The child’s body weight was measured (while wearing only underwear and while barefoot) to the nearest 0.1 kg using a portable digital model 899 scale (SECA). Body mass index (BMI, measured in kg/m²) was calculated using the weight and height measurements. BMI data were used to study whether the child’s weight status affected the parents’ willingness to participate in our study and/or complete the e-learning program.

Descriptive analyses will be used to determine whether randomization resulted in a balanced distribution of key demographic variables (e.g., the child’s age, gender and grade in school, as well as the parents’ education level and ethnic background) and the baseline primary and secondary outcomes. Continuous variables will be presented as the mean ± SD, and categorical data will be presented as the percentage of respondents within each of the possible categories. Moreover, the variables that had differing distributions between the two groups will be entered as confounders in all models that test the effectiveness of the e-learning program. The effect of the e-learning program on changes in the child’s dietary behavior, sedentary behavior, and physical activity, as well as the parenting style, parenting practices, and parental self-efficacy, will be tested in accordance with the intention-to-treat principle and in a completers-only framework using Mplus [39]. Intention-to-treat means that all participants will be analyzed in the condition to which they were randomly assigned. Missing data will be handled by multiple imputation. A total of 50 datasets will be completed using multiple imputation. Mplus will read the 50 datasets using the TYPE = IMPUTATION option and will perform the desired analyses for each dataset. Mediating the parameter estimates will then aggregate the results of the 50 analyses. With respect to the completers-only analyses, only the participants with scores at all time points will be included. In both the intention-to-treat and the completers-only analyses, the effect of the intervention condition will be compared to the control condition. Because the data have a multilevel structure (i.e., individuals are “clustered” within school grades), the individual respondents may not necessarily be independent within each grade. To correct for the potential non-independence (complexity) of the data, the TYPE = COMPLEX procedure in Mplus will be used; this procedure corrects the standard errors of the parameter estimates for dependency, yielding unbiased estimates. Finally, the results will be reported in accordance with CONSORT (Consolidated Standards of Reporting Trials) [40,41].

The recruitment and inclusion of participants began at the end of 2012. The baseline data were collected from January 2013 through December 2013. After the baseline data were collected the participants were randomized in February 2013 and September 2013. For each parent–child dyad, the follow-up measurements were collected at fixed time points, 5 and 12 months after the baseline measurements (see Table 1). All data were continuously collected, entered. The data will be analyzed and the results will be reported after the completion of the final follow-up measurements collected 12 months after baseline.