Table 2.

Summary of the input and output variables considered in the model building.

Variable		Description	Values
Input variables
	Radius	Radiologists’ assessments of the Radius growth zone	Stage 1; Stage 2; Stage 3; Stage 4a; Stage 4b; Stage 4c; Stage 5
	Distal femur	Radiologists’ assessments of the distal femur growth zone	Stage 1; Stage 2; Stage 3; Stage 4a; Stage 4b; Stage 4c; Stage 5
	Proximal tibia	Radiologists’ assessments of the proximal tibia growth zone	Stage 1; Stage 2; Stage 3; Stage 4a; Stage 4b; Stage 4c; Stage 5
	Distal tibia	Radiologists’ assessments of the distal tibia growth zone	Stage 1; Stage 2; Stage 3; Stage 4a; Stage 4b; Stage 4c; Stage 5
	Calcaneus	Radiologists’ assessments of the calcaneus growth zone	Stage 1; Stage 2; Stage 3; Stage 4a; Stage 4b; Stage 4c; Stage 5
	BMI	Body mass index of the participant, calculated as in the equation (1)	Numeric
	Residence	Type of residence the participant lives in (or lived during upbringing)	Rented; owned
	Physical activity	The participants’ daily level of activity	Highly inactive; inactive; little active; active; highly active
	Parent origin	Origin of the participants’ parents, regarding if they were born outside Sweden or not	No foreign-born parents; one foreign-born parent; both foreign-born parents
	Tanner scale	Self-assessed Tanner Scale for pubertal growth [33,34]	Stage 1; Stage 2; Stage 3; Stage 4; Stage 5
Output variables
	Minor	Characterizes the participant as being a minor or not, regarding the threshold of 18 years. This is the output variable for the binary classification models	Yes; no
	Age	Regards the age group which the participant belongs to. This is the output variable for the multi-class classification models	14; 15; 16; 17; 18; 19; 20; 21