Document is current

Article History

Received: 28 July 2025

Accepted: 25 February 2026

First Online: 25 March 2026

Declarations

:

: This study was approved by the Medical Ethical Committee of the VU University Medical Centre, protocol #2016.415. Due to changes in privacy legislation in the Netherlands during the study, as of May 2018 we removed children’s unique identifiers, date of birth, and age from their questionnaires to protect their privacy. Our study was preregistered, protocol #ISRCTN76414974. No traceable personal data were used; all data used were made anonymous to the entire research team. This study was conducted according to the guidelines laid down in the Declaration of Helsinki, and all procedures involving research study participants were approved by the VU University Medical Centre, protocol #2016.415.

: Prior to data collection, parents received an information letter about the study with an explanation of the opt-out procedures to withdraw their child(ren) from participation in this study. Participation in the intervention was outside the scope of this study, as this was part of the standard practice of the Public Health Service of Amsterdam. Parents received an opt-in option for the parent questionnaire. All measurements were collected in accordance with organizational legislation, and the research protocol was approved by the Medical Ethical Committee of the VU University Medical Centre, protocol #2016.415. Due to changes in privacy legislation in the Netherlands during the study, as of May 2018 we removed children’s unique identifiers, date of birth, and age from their questionnaires to protect their privacy. This meant we could not follow children individually over time, but we had to compare cohorts to one another.

: Not applicable.

: The authors state that they have no competing interests.