Centre for Health, Activity and Rehabilitation Research (Drs van der Linden, Jagadamma, and Mercer and Ms Dufton), Queen Margaret University Edinburgh, Musselburgh, United Kingdom; Royal Hospital for Sick Children (Drs Wordie and Gaston and Ms Hunter), Edinburgh, United Kingdom; School of Medicine (Dr Robb), University of St Andrews, St Andrews, United Kingdom.

Marietta L. van der Linden, PhD, Centre for Health, Activity and Rehabilitation Research, Queen Margaret University Edinburgh, Queen Margaret University Dr, Musselburgh EH21 6UU, United Kingdom ([email protected]).

This work was supported by funding from Edinburgh & Lothian Health Foundation no. 109/600.

The authors declare no conflicts of interest.

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