Footnotes

• Contributors SC conceptualised the study design, analysed the data and drafted the manuscript. CSB, PCP and KT provided input on the study design and results. EP contributed to the data analysis plan and provided input on the study design and results. All authors critically reviewed the draft manuscript and approved the final manuscript as submitted.

• Competing interests None declared.

• Ethics approval Sick Kids Research Ethics Board.

• Provenance and peer review Not commissioned; internally peer reviewed.