Funding for this research was provided by:
H2020 European Research Council (REACH 648837)
Economic and Social Research Council (ES/S012567/1)
Received: 29 May 2020
Accepted: 13 April 2021
First Online: 3 May 2021
Change Date: 29 November 2021
Change Type: Correction
Change Details: A Correction to this paper has been published:
Change Details: https://doi.org/10.1186/s12889-021-12258-7
: All pupils gave informed assent prior to completing the questionnaire. All parents/carers were informed about the study and given the opportunity to opt their child out of the study. This opt-out parental consent approach maximises participation, minimises selection bias, and avoids the loss of willing participants due to administrative challenges of written parental consent (e.g. forgetting to bring in forms). Schools tend to prefer this inclusive approach as it is easier to timetable and less disruptive. This is the approach commonly used in school-based research [CitationRef removed, CitationRef removed]. All study procedures, including opt-out parental consent, and measures were approved by the Psychiatry, Nursing and Midwifery Research Ethics Subcommittee (PNM RESC), King’s College London (ref: 15/162320).
: Not Applicable
: The authors declare that they have no competing interests.