Funding for this research was provided by:
Canadian Institutes of Health Research (Vanier Graduate Scholarship & Michael Smith Travel Supplement)
Medical Research Council (MR/K023209/1)
Medical Research Council (MR/K007017/1)
Received: 25 September 2018
Accepted: 16 May 2019
First Online: 28 May 2019
Compliance with ethical standards
: The authors have no conflict of interest.
: The Growing Up in Scotland cohort survey collection was approved by the Scotland ‘A’ Medical Research Ethics Committee. Informed consent was obtained from all participants. Use of the Growing Up in Scotland cohort data was approved by the UK Data Service, and by the ethics review process of the University of Edinburgh’s Usher Institute of Population Health Sciences and Informatics. All data collection and analysis procedures were in accordance with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.