Preventive post-divorce group programs Tough Turtles and Courageous Dinosaurs: process and preliminary impact evaluation
| ISRCTN | ISRCTN77225129 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN77225129 |
| Sponsor | TNO Child Health |
| Funder | TNO Child Health |
- Submission date
- 06/02/2026
- Registration date
- 13/04/2026
- Last edited
- 13/04/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
Parental separation and divorce impact millions of children worldwide, including approximately 86,000 each year in the Netherlands.
Studies have found that children of post-divorce, on average, perform less well in school, exhibit more behavioral problems, score lower in psychological and emotional well-being, and have less self-confidence (Amato & James, 2010; den Hollander, 2017).
Tough Turtles and Courageous Dinosaurs are scientifically supported preventive group training programs for children in primary school—whose parents are divorced. The training is designed to support post-divorce resilience.
Previous research demonstrated positive effects on child psychosocial functioning and high appreciation among families and professionals. Sustaining effectiveness requires ongoing monitoring of implementation and outcomes.
This study focuses on the following two objectives:
1. What are the parental expectations, appreciation and goal attainment with the programs provided?
2. To what extent do the Tough Turtles and Courageous Dinosaurs programs have impact on child well-being and psychosocial functioning?
Who can participate?
Parents of children participating in the Tough Turtles and Courageous programs may participate in the study.
What does the study involve?
The children participate in the intervention in group settings (up to 6 (Turtles) or 7 (dinosaurs) per group. A total of 41 groups take part in this study. Providers of the training programs are asked to assist in recruiting parents for the process evaluation. All parents of the children participating in these trainings will be invited to complete online questionnaires.
What are the possible benefits and risks of participating?
We are evaluating an existing training program that has already been implemented nationwide for quite some time. The aim of the study is a process and a preliminary impact evaluation. In other words, data collection is limited to parents’ opinions about the implementation of the training, along with a questionnaire focused on the effects of the training on any behavioral and emotional problems in the child. The trainers do not see the answers of the parents. We expect that the risks of participating on the study will be small.
Where is the study run from?
Research institute TNO in the Netherlands.
When is the study starting and how long is it expected to run for?
Start date: 20 August 2024. End date: 28 February 2026
Who is funding the study?
Research institute TNO in the Netherland.
Who is the main contact?
Mariska Klein Velderman, Mariska.kleinvelderman@tno.nl
Contact information
Public, Scientific, Principal investigator
Sylviusweg 71
Leiden
2333 BE
Netherlands
| Phone | +31 646966095 |
|---|---|
| meinou.theunissen@tno.nl |
Principal investigator
Sylviusweg 71
Leiden
2333 BE
Netherlands
| Phone | +31 654974377 |
|---|---|
| mariska.kleinvelderman@tno.nl |
Study information
| Primary study design | Interventional |
|---|---|
| Study design | A pre- and post-measurement design was used in this study. |
| Secondary study design | Non randomised study |
| Scientific title | Post-divorce group programs Tough Turtles and Courageous Dinosaurs: process and preliminary impact evaluation |
| Study objectives | This study aims to evaluate the intervention process and preventive potential of the post-divorce group interventions Tough Turtles (TT) and Courageous Dinosaurs (CD), adapted from the U.S. Children of Divorce Intervention Program. Specifically, we assess process indicators and explore preliminary impact on child wellbeing and emotional coping using a pre-experimental design. By updating evidence from Dutch practice, the study contributes to global discussions on effective preventive strategies for children experiencing parental divorce. 1. Process indicators - Expectations, appreciation, goal attainment 2. Preventive potential - well-being and psychosocial functioning. |
| Ethics approval(s) |
Approved 24/07/2024, Ethics committee of the Netherlands Organization for Applied Scientific Research (Sylviusweg 71, Leiden, 2333 BE, Netherlands; +31 613738409; jan.venerp@tno.nl), ref: 2024-078 |
| Health condition(s) or problem(s) studied | Supporting young children's (4-8 years old) post-divorce resilience. |
| Intervention | Procedure During the intervention, children participated in 12 weekly group sessions (up to six Turtles) or 7 (dinosaurs) children per group. As part of the evaluation, parents were invited to complete two online questionnaires: at the start (pre-test) and at the end (post-test) of the intervention. These questionnaires cover: Process aspects: expectations (pre-test), program appreciation, and goal attainment (post-test). Impact aspects: child well-being and psychosocial functioning. Operationalization Process measures Example items: expectations regarding the program (pre-test), most and least appreciated elements, overall rating (numeric score), achievement of program goals, missing elements, and satisfaction with duration and number of sessions (post-test). Impact measures Well-being: assessed using the Cantril ladder (single item 1-10 scale; Cantril, 1965). Psychosocial functioning: assessed with PSYCAT, an online parent questionnaire designed to detect behavioral and emotional problems in children, including internalizing and externalizing problems, hyperactivity, and overall difficulties. PSYCAT uses Computerized Adaptive Testing (CAT) to tailor questions to the respondent for efficient and precise measurement (Theunissen et al., 2020). Missing data are addressed through multiple imputation performed in R. |
| Intervention type | Behavioural |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) | |
| Completion date | 28/02/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Mixed |
| Lower age limit | 18 Years |
| Upper age limit | 99 Years |
| Sex | All |
| Target sample size at registration | 75 |
| Key inclusion criteria | Parents of children participating in post-divorce group interventions Tough Turtles and Courageous Dinosaurs |
| Key exclusion criteria | Does not meet inclusion criteria |
| Date of first enrolment | 01/09/2024 |
| Date of final enrolment | 28/02/2026 |
Locations
Countries of recruitment
- Netherlands
Study participating centre
Netherlands
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | The datasets generated during and/or analyzed during the current study will be available upon request from Mariska Klein Velderman, Mariska.Kleinvelderman@tno.nl |
Editorial Notes
06/02/2026: Trial's existence confirmed by Ethics committee of the Netherlands Organization for Applied Scientific Research.
